Since this is a relation between
concepts
I call it a second level relation, whereas the former relation I call a first level relation.
Gottlob-Frege-Posthumous-Writings
All the same something is asserted of a concept in our sentence.
We can even say that our concept is presented as falling under a higher one*-one whose sole characteristic mark is is realized, understanding this word in the sense in which we are using it in the present context.
But this does not in any way efface
the distinction between concept and object. We see to begin with that in the expression 'There is at least one square root of 4', 'square root of 4' is being used predicatively: 'there is something that is a square root of 4'. In place of this we could say 'there is something that has the property of giving the result 4 when multiplied by itself. Hence what is here asser-
* In my Grundlagen I called such a concept a second order concept; in my Funktion und Begriff I called it a second level concept, as I shall do here.
? proper name can never be a pre- dicative expression, though it can be partofone. Idonotwanttosayitis false to assert about an object what is here asserted about a concept; I want to say it is impossible, sense- less, to do so.
The sentence 'there is Julius Caesar' is neither true nor false but senseless; the sentence 'there is a man whose name is Julius Caesar' has a sense, but here again we have a concept, as the indefinite article shows. We get the same thing in the sentence 'there is only one Vienna'. We must not let ourselves be deceived because language often uses the same word now as a proper name, now as a concept-word; in our example, the numeral indicates that we have the latter; 'Vienna' is here a concept-word, like ? metropolis'. Using it in this sense, we may say: 'Trieste is no Vienna'. If, on the other hand, we substitute 1201] 'Julius Caesar' for the proper name formed by the first six words of the sentence 'the concept square root of 4 is realized', we get a sentence that has a sense but is false; for the assertion that some- thing is realized (as the word is being taken here) can be truly made only about a quite special kind of objects, viz. such as can be designated by proper names of the form 'the concept F'. Thus the words 'the concept square root of 4' have an
ted of a concept can never be asserted of an object. This is not to saythatitisfalsetodothis,butim- possible: a sentence which tried to express such a thing would be absolutely devoid of sense; for it has no sense to use the name of an object predicatively. We have seen that even where the form of a sentence makes it look as if this is being done, the truth is that the object forms only part of what is asserted, since 'nothing other than' has to be added in thought. A sentence such as 'There is at least Julius Caesar' is senseless, although the sentence 'There is at least one man whose name is "Julius Caesar"' has a sense; but here again we have a concept, as the 'one' shows.
On Concept and Object 109
If, on the other hand, we sub- stitute the proper name 'Julius Caesar' for the proper name formed by the first six words of the sentence 'The concept square root of 4 is realized', we get a sentence that has a sense but is false; for the assertion that something is realized, as the word is meant here, is one we can only truly make of such objects as stand in a quite special relation to a concept. Thus the words 'the con- cept square root of 4' have an essentially different behaviour, as
? 110 On Concept and Object
essentially different behaviour, as regards possible substitutions, from the words 'square root of 4' in our original sentence; i. e. the reference of the two phrases is essentially
different.
What has been shown here in one
example holds good generally; the behaviour of the concept is essen- tially predicative, even where some- thing is being asserted about it; consequently it can be replaced there only by another concept, never by an object. Thus the assertion that is made about a concept does not suit an object. Second-level con- cepts, which concepts fall under, are essentially different from first-level concepts, which objects fall under.
regards possible substitutions, from the words 'square root of 4' in our original sentence; i. e. the meanings of the two properties are different, thoughrelated.
What has been shown here in one example holds good generally: the behaviour of the concept is essen- tially predicative even when some- thing is being asserted of it; conse- quently it can be replaced there only by another concept, never by an object; i. e. the assertion that is made about a concept does not fit an object at all. Moreover a concept (of second level) under which a concept falls is essentially different from a concept (of first level) under which objects fall.
In the sentence 'There is at least one square root of 4' we assert that the first level concept square root of 4 falls under a concept of second level, whereas in the sentence 'The concept square root o f 4 is realized' we assert that the object the concept square root of4 falls under the first level concept concept that is realized. We do indeed have the same thought in the two concepts, [sic. ] but this, being analysed dif- ferently, is construed in a different way.
The relation of an object to a concept that it falls under is dif- ferent from the admittedly similar relation of a concept to a concept (of second level). From now on we shall give parallel expression to the similarity and the difference by saying than an object falls under a concept, and a concept falls within a concept (of second level); for, strictly speaking, we have been making a mistake in using the same
The relation of an object to a first-level concept that it falls under is different from the (admittedly similar) relation of a first-level to a second-level concept. (To do justice at once to the distinction and to the similarity, we might perhaps say: An object falls under a first-level concept; a concept falls within a second-level concept. ) The dis- tinction of concept and object thus still holds, with all its sharpness.
? With this there hangs together what I have said (Grund/agen, ? 53) about my usage of the words 'property' and 'mark'; Kerry's dis- cussion gives me occasion to revert once more to this.
The words serve to signify relations, in sentences like ? (/J is a property of T' and '(/J is a mark of il'. In my way of speaking a thing can at once be a property and a mark but not of the same
thing.
words to cover both cases. From this we can see that the distinction between object and concept still holds in all its sharpness.
Connected with this is another distinction, namely that between property and characteristic mark. I have already explained this in ? 53 of my Grundlagen and at the time I thought I had made it sufficiently clear. Since, however, Kerry makes no use of it and falls into error as a result, I can only assume, alas, that he has not understood me; this time I will try to be more successful.
The words 'property' and 'characteristic mark' serve to designate relations such that something can at the same time be a property of r and a characteristic mark of L1. We express ourselves more precisely if we use the words 'characteristic mark' only in the phrase 'characteristic mark of a concept'. If a thing is a property of an object, then it is a characteristic mark of a first level concept. We may also speak of properties of a first level concept, and these will then be characteristic marks of second level concepts. I will call the concepts under which an object falls its properties.
If the object r has the properties (/J, X and '1', I may combine them into n; so that it is the same thing if I say that r has the property n, or, that r has the property (/J and r has the property X and r has the property '1'. I then call (/J, X, and 'I' marks of the concept n, and, at the same time, properties of r. It is clear that the relations of (/J to r and to n are
I call the concepts under which an object falls its properties; thus 'to be (/J is a property of T' is just another way of saying: 'T falls under the concept of a (/J'. If the object r has the properties (/), X, and '1', I may combine them into n; so that it is the same thing if I say that r has the [202] property n, or, that r has the properties (/), X, and '1'. I then call (/J, X, and 'I' marks of the concept n, and, at the same time, properties of r. It is clear that the relations of (/J to r and to n are quite different, and that conse-
On Concept and Object Ill
? 112 On Concept and Object
quently different terms are required. quite different; r falls under the r falls under the concept f/J; but n, concept f/J; but n, which is itself a which is itself a concept, cannot fall concept, cannot fall under the first under the first-level concept f/J; only level concept f/J; only to a second to a second-level concept could it level concept could it stand in a
stand in a similar relation. n is, on the other hand, subordinate to f/J.
Let us consider an example. Instead of saying:
'2 is a positive number' and '2 is a whole number' and '2 is less than 10'.
we may also say
'2 is a positive whole number less than 10'.
Here
appear as properties of the object 2, and also as marks of the concept
positive whole number less than 10.
This is neither positive, nor a whole number, nor less than 10. It is indeed subordinate to the concept whole number , b u t d o e s n o t fall under it.
Let us now compare with this what Kerry says in his second article (p. 424). 'By the number 4 we understand the result of additively combining 3 and 1. The concept object here occurring is the numerical individual 4; a quite definite number in the natural number-series. This object obviously bears just the marks that are named in its concept, and no others besides-provided we refrain, as we
similar relation.
to be a positive number, to be a whole number, to be less than 10,
? ? surely must, from counting as propria of the object its infinitely numerous relations to all other individual numbers; "the" number 4 is likewise the result of additively combining 3 and 1. '
We see at once that my dis- tinction between property and mark is here quite slurred over. Kerry distinguishes here between the num- ber 4 and 'the' number 4. I must confess that this distinction is in- comprehensible to me. The number 4 is to be a concept; 'the' number 4 is to be a concept-object, and none other than the numerical individual 4. It needs no proof that what we have here [203] is not my distinction between concept and object. I t almost looks as though what was floating (though very obscurely) before Kerry's mind were my dis- tinction between the sense and the reference of the words 'the number 4'. * But it is only of the reference of the words that we can say: this is the result of additively combining 3 and 1.
Again, how are we to take the word 'is' in the sentences 'the num- ber 4 is the result of additively combining 3 and I' and '"the" number 4 is the result of additively combining 3 and I'? Is it a mere copula, or does it help to express a logical equation? In the first case, 'the' would have to be left out before 'result', and the sentences would go like this:
'The number 4 is a result of addi- tively combining 3 and I';
* Cf. my essay 'On Sense and Reference' (cited above).
On Concept and Object 113
? 114 On Concept and Object '"The" number 4 is a result of
additively combining 3 and 1. "
In that case, the objects that Kerry designates by
'the number 4' and "'the" number 4' would both fall under the concept result o f additively combining 3
and 1.
And then the only question would be what difference there was be- tween these objects. (I am here using the words 'object' and 'concept' in my accustomed way. ) I should express as follows what Kerry is apparently trying to say:
'The number 4 has those properties, and those alone, which are marks of the concept: result ofadditively combining 3 and 1. '
I should then express as follows the sense of the first of our two sen- tences:
'To be a number 4 is the same as being a result of additive com- bination of 3 and 1. '
In that case, what I conjectured just now to have been Kerry's intention could also be put thus:
'The number 4 has those properties, and those alone, which are marks of the concept a number 4. '
[204] (We need not here decide whether this is true. ) The inverted commas around the definite article in the words '"the" number 4' could in that case be omitted.
But in these attempted in- terpretations we have assumed that in at least one of the two sentences the definite articles in front of 'result'
? and 'number 4' were inserted only by an oversight. It we take the words as they stand, we can only regard them as having the sense of a logical equation, like:
'The number 4 is none other than the result of additively combining 3 and 1. '
The definite article in front of 'result' is here logically justified only if it is known (i) that there is such a result; (ii) that there is not more than one. In that case, the phrase designates an object, and is to be regarded as a proper name. If both of our sen- tences were to be regarded as logical equations, then, since their right sides are identical, it would follow from them that the number 4 is 'the' number 4, or, if you prefer, that the number 4 is no other than 'the' number 4; and so Kerry's dis- tinction would have been proved untenable. However, it is not my present task to point out contra- dictions in his exposition; his way of taking the words 'object' and 'con- cept' is not properly my concern here. I am only trying to set my own usage of these words in a clearer light, and incidentally show that in any case it differs from his, whether that is consistent or not.
I do not at all dispute Kerry's right to use the words 'concept' and 'object' in his own way, if only he would respect my equal right, and admit that with my use of terms I have got hold of a distinction of the highest importance. I admit that there is a quite peculiar obstacle in the way of an understanding with my reader. By a kind of necessity of language, my expressions, taken
On Concept and Object
115
? 116
On Concept and Object
literally, sometimes miss my thought; I mention an object, when what I intend is a concept. I fully realize that in such cases I was relying upon a reader who would be ready to meet me half-way-who does not begrudge a pinch of salt.
Somebody may think that this is an artificially created difficulty; that there is no need at all to take account of such an unmanageable thing as what I call a concept; that one might, like Kerry, regard an object's falling under a concept as a relation, in which the same thing could occur now as object, now as concept. [205] The words 'object' and 'concept' would then serve only to indicate the different positions in the relation. This may be done; but anybody who thinks the difficulty is avoided this way is very much mistaken; it is only shifted. For not all the parts of a thought can be complete; at least one must be 'un- saturated', or predicative; otherwise they would not hold together. For example, the sense of the phrase 'the number 2' does not hold together with that of the expression 'the concept prime number' without a link. We apply such a link in the sentence 'the number 2 falls under the concept prime number'; it is contained in the words 'falls under', which need to be completed in two ways-by a subject and an ac- cusative; and only because their sense is thus 'unsaturated' are they capable of serving as a link. Only when they have been supplemented in this twofold respect do we get a complete sense, a thought. I say that such words or phrases stand for a relation. We now get the same
? difficulty for the relation that we were trying to avoid for the concept. For the words 'the relation of an object to the concept it falls under' designate not a relation but an object; and the three proper names 'the number 2', 'the concept prime number', 'the relation of an object to a concept it falls under', hold aloof from one another just as much as the first two do by themselves; however we put them together, we get no sentence. It is thus easy for us to see that the difficulty arising from the 'unsaturatedness' of one part of the thought can indeed be shifted, but not avoided. 'Complete' and 'un- saturated' are of course only figures of speech; but all that I wish or am able to do here is to give hints.
It may make it easier to come to un understanding if the reader com- pares my work Function und BegrifJ. For over the question what it is that is called a function in Analysis, we come up against the same obstacle; and on thorough investigation it will be found that the obstacle is essential, and founded on the nature of our language; that we cannot avoid a certain inap- propriateness of linguistic ex- pression; and that there is nothing for it but to realize this and always take it into account.
On Concept and Object 117
? ? [Comments on Sense and Meaning] 1 [1892-1895]
In an article (Uber Sinn und Bedeutung) I distinguished between sense and meaning in the first instance only for the case of proper names (or, if one prefers, singular terms). The same distinction can also be drawn for concept? words. Now it is easy to become unclear about this by confounding the division into concepts and objects with the distinction between sense and meaning, so that we run together sense and concept on the one hand and meaning and object on the other. To every concept-word or proper name, there corresponds as a rule a sense and a meaning, as I use these words. Of course in fiction words only have a sense, but in science and wherever we are concerned about truth, we are not prepared to rest content with the sense, we also attach a meaning to proper names and concept-words; and if through some oversight, say, we fail to do this, then we are making a mistake that can easily vitiate our thinking. The meaning of a proper name is the object it designates or names. A concept-word means a concept, if the word is used as is appropriate for logic. I may clarify this by drawina attention to a fact that seems to weigh heavily on the side of extensionalist as against intensionalist logicians: namely, that in any sentence we can substitute salva veritate one concept-word for another if they have the same extension, so that it is also the case that in relation to inference, and where the laws of logic are concerned, that concepts differ only in so far as their extensions are different. The fundamental logical relation is that of an object's falling under a concept: all relations between concepts can be reduced to this. If an object falls under a concept, it falls under all concepti with the same extension, and this implies what we said above. Therefore just as proper names can replace one another salva veritate, so too can concept? words, if their extension is the same. Of course the thought will alter when such replacements are made, but this is the sense of the sentence, not ita meaning. * The meaning, which is the truth-value, remains the same. For thia reason we might easily come to propose the extension of a concept as the
* Cf. my article Uber Sinn und Bedeutung.
1 These comments were not composed before 1892, the year in which the article Ober Sinn und Bedeutung appeared. They are part of a bundle of papers entitled 'Schrodersche Logik', which existed in a complete form prior to the destruction of the NachlajJ. The first part of these constituted a draft of Frege's article Kritischl Beleuchtung einiges Punkte in E. Schroder's Vorlesungen iiber die Algebra der
Logik (ed. ).
? [Comments on Sense and Meaning] 119
meaning of a concept-word; to do this, however, would be to overlook the fact that the extensions of concepts are objects and not concepts (Cf. my essay Funktion und Begrifl). Nevertheless there is a kernel of truth in this position. In order to bring it out, I need to advert to what I said in my mono- graph on Funktion und Begriff. On the view expressed there a concept is a function of one argument, whose value is always a truth-value. Here I am borrowing the term 'function' from Analysis and, whilst retaining what is essential to it, using it in a somewhat extended meaning, a procedure for which the history of Analysis itself affords a precedent. The name of a func- tion is accompanied by empty places (at least one) where the argument is to go; this is usually indicated by the letter 'x' which fills the empty places in 4uestion. But the argument is not to be counted as belonging to the function, und so the letter 'x' is not to be counted as belonging to the name of the function either. Consequently one can always speak of the name of a function as having empty places, since what fills them does not, strictly speaking, belong to them. Accordingly I call the function itself unsaturated, or in need of supplementation, because its name has first to be completed with the sign of an argument if we are to obtain a meaning that is complete in itself. I call such a meaning an object and, in this case, the value of the function for the argument that effects the supplementing or saturating. In the cases we first encounter the argument is itself an object, and it is to these that we shall mainly confine ourselves here. Now with a concept we have the special case that the value is always a truth-value. That is to say, if we complete the name of a concept with a proper name, we obtain a sentence whose sense is a thought; and this sentence has a truth value as its meaning. To acknowledge this meaning as that of the True (as the True) is to judge that the object which is taken as the argument falls under the concept. What in the case of a function is called unsaturatedness, we may, in the case of a concept, call its predicative nature. ? This comes out even in the cases in which we speak of a subject-concept ('All equilateral triangles are equiangular' means 'If anything is an equilateral triangle, then it is an equiangular triangle').
Such being the essence of a concept, there is now a great obstacle in the way of expressing ourselves correctly and making ourselves understood. If I want to speak of a concept, language, with an almost irresistible force, compels me to use an inappropriate expression which obscures-! might nlmost say falsities-the thought. One would assume, on the basis of its 1malogy with other expressions, that if I say 'the concept equilateral triangle' I am designating a concept, just as I am of course naming a planet If I say 'the planet Nepture'. But this is not the case; for we do not have anything with a predicative nature. Hence the meaning of the expression 'the
? The words 'unsaturated' and 'predicative' seem more suited to the sense than the meaning; still there must be something on the part of the meaning which corresponds to this, and I know of no better words.
Cf. Wundt's Logik.
? 120 [Comments on Sense and Meaning]
concept equilateral triangle' (if there is one in this case) is an object. We cannot avoid words like 'the concept', but where we use them we must always bear their inappropriateness in mind. ? From what we have said it follows that objects and concepts are fundamentally different and cannot stand in for one another. And the same goes for the corresponding words or signs. Proper names cannot really be used as predicates. Where they might seem to be, we find on looking more closely that the sense is such that they only form part of the predicate: concepts cannot stand in the same relations as objects. It would not be false, but impossible to think of them as doing so. Hence, the words 'relation of a subject to a predicate' designate two quite different relations, according as the subject is an object or is itself a concept. Therefore it would be best to banish the words 'subject' and 'predicate' from logic entirely, since they lead us again and again to confound two quite different relations: that of an object's falling under a concept and that of one concept being subordinated to another. The words 'all' and 'some', which go with the grammatical subject, belong in sense with the grammatical predicate, as we see if we go over to the negative (not all, nonnulli}. From this alone it immediately follows that the predicate in these cases is different from that which is asserted of an object. And in the same way the relation of equality, by which I understand complete coincidence, identity, can only be thought of as holding for objects, not concepts. If we say 'The meaning of the word "conic section" is the same as that of the concept-word "curve of the second degree"' or 'The concept conic section coincides with the concept curve o f the second degree', the words 'meaning of the concept-word "conic section"' are the name of an object, not of a concept; for their nature is not predicative, they are not unsaturated, they cannot be used with the indefinite article. The same goes for the words 'the concept conic section'. But although the relation of equality can only be thought of as holding for objects, there is an analogous relation for concepts.
Since this is a relation between concepts I call it a second level relation, whereas the former relation I call a first level relation. We say that an object a is equal to an object b (in the sense of completely coinciding with it) if a falls under every concept under which b falls, and conversely. We obtain something corres- ponding to this for concepts if we switch the roles of concept and object. We could then say that the relation we had in mind above holds between the concept ([> and the concept X, if every object that falls under ([> also falls under X, and conversely. Of course in saying this we have again been unable
to avoid using the expressions 'the concept ([>','the concept X', which again obscures the real sense. So for the reader who is not frightened of the concept-script I will add the following: The unsaturatedness of a concept (of first level) is represented in the concept-script by leaving at least one empty place in its designation where the name of the object which we are saying falls under the concept is to go. This place or places always has to be filled
? I shall deal with this difficulty.
? ? [Comments on Sense and Meaning] 121
in some way or other. Besides being filled by a proper name it can also be filled by a sign which only indicates an object. We can see from this that the sign of equality, or one analogous to it, can never be flanked by the designation of a concept alone, but in addition to the concept an object must also be designated or indicated as well. Even if we only indicate concepts schematically by a function-letter, we must see to it that we give expression to their unsaturatedness by an accompanying empty place as in C/>( ) and X( ). In other words, we may only use the letters (cl>, X}, which are meant to indicate or designate concepts, as function-letters, i. e. in such a way that they are accompanied by a place for the argument (the space between the following brackets). This being so, we may not write cp = X, because here the letters cp and X do not occur as function-letters. But nor may we write C/>( ) = X( }, because the argument-places have to be filled. But when they are filled, it is not the functions (concepts) themselves that are put equal to one another: in addition to the function-letter there will be something else on either side of the equality sign, something not belonging to the function.
These letters cannot be replaced by letters that are not used as function- letters: there must always be an argument-place to receive the 'd. The idea might occur to one simply to write cp = X. This may seem all right so long as we are indicating concepts schematically, but a mode of designation that is really adequate must provide for all cases. Let us take an example which I have already used in my paper on Funktion und Begriff.
For every argument the function x 2 = 1 has the same (truth-} value as the function (x + 1}2 = 2(x + 1) i. e. every object falling under the concept less by 1 than a number whose square is equal to its double falls under the concept square root of1 and conversely. If we expressed this thought in the
way that we gave above, 1 we should have
(al=1)~ ((a+1}2=2(a+1))
What we have here is that second level relation which corresponds to, but should not be confused with, equality (complete coincidence) between objects. If we write it-0-~(a2 = 1) = ((a + 1)2 = 2(a + 1}}, we have expressed what is essentially the same thought, construed as an equation between values of functions that holds generally. We have here the same second level relation; we have in addition the sign of equality, but this does not suffice on its own to designate this relation: it has to be used in combination with the sign for generality: in the first line we have a general statement but not an equation. In e(e2 = 1) = il((a + 1)2 = 2(a + 1}} we do have an equation, but not between concepts (which is impossible} but between objects, namely extensions of concepts.
Now we have seen that the relation of equality between objects cannot be
1 It may be that the notation used in the following formula, which Frege has not explained above, was introduced in the lost first part of the manuscript (see footnote lop. II8)(ed. ).
? ? 122 [Comments on Sense and Meaning]
conceived as holding between concepts too, but that there is a correspond- ing relation for concepts. It follows that the word 'the same' that is used to designate the former relation between objects cannot properly be used to designate the latter relation as well. If we try to use it to do this, the only recourse we really have is to say 'the concept ([> is the same as the concept X' and in saying this we have of course named a relation between objects,? where what is intended is a relation between concepts. We have the same case if we say 'the meaning of the concept-word A is the same as that of the concept word B'. Indeed we should really outlaw the expression 'the meaning of the concept-word A', because the definite article before 'meaning' points to an object and belies the predicative nature of a concept. It would be better to confine ourselves to saying 'what the concept word A means', for this at any rate is to be used predicatively: 'Jesus is, what the concept word "man" means' in the sense of 'Jesus is a man'.
Now if we bear all this in mind, we shall be well able to assert 'what two concept-words mean is the same if and only if the extensions of the corresponding concepts coincide' without being led astray by the improper use of the word 'the same'. And with this statement we have, I believe, made an important concession to the extensionalist logicians. They are right when they show by their preference for the extension, as against the intension, of a concept that they regard the meaning and not the sense of words as the essential thing for logic. The intensionalist logicians are only too happy not to go beyond the sense; for what they call the intension, if it is not an idea, is nothing other than the sense. They forget that logic is not concerned with how thoughts, regardless of truth-value, follow from thoughts, that the step from thought to truth-value-more generally, the step from sense to meaning-has to be taken. They forget that the laws of logic are first and foremost laws in the realm of meanings and only relate indirectly to sense. If it is a question of the truth of something-and truth is the goal of logic-we also have to inquire after meanings; we have to throw aside proper names that do not designate or name an object, though they may have a sense; we have to throw aside concept-words that do not have a meaning. These are not such as, say, contain a contradiction-for there is nothing at all wrong in a concept's being empty-but such as have vague boundaries. It must be determinate for every object whether it falls under a concept or not; a concept word which does not meet this requirement on its meaning is
meaningless. E. g. the word 'wiJ). v' (Homer, Odyssey X, 305) belongs to this class, although it is true that certain characteristic marks are supplied. For this reason the context cited need not lack a sense, any more than other contexts in which the name 'Nausicaa', which probably does not mean or name anything, occurs. But it behaves as if it names a girl, and it is thus assured of a sense. And for fiction the sense is enough. The tkought, though it is devoid of meaning, of truth-value, is enough, but not for science.
? These objects have the names 'the concept ([>'and 'the concept X'.
? ? ? [Comments on Sense and Meaning] 123
In my Grundlagen and the paper Uber formale Theorien der Arithmetik I showed that for certain proofs it is far from being a matter of indifference whether a combination of signs--e. g. F l - h a s a meaning* or not, that, on the contrary, the whole cogency of the proof stands or falls with this. The meaning is thus shown at every point to be the essential thing for science. Therefore even if we concede to the intensionalist logicians that it is the concept as opposed to the extension that is the fundamental thing, this does not mean that it is to be taken as the sense of a concept-word: it is its meaning, and the extensionalist logicians come closer to the truth in so far us they are presenting-in the extension-a meaning as the essential thing. Though this meaning is certainly not the concept itself, it is still very closely connected with it.
1
Husserl takes Schr6der to task for the unclarity in his discussion of the words 'unsinnig' [without sense], 'einsinnig' [having one sense], and 'mehrsinnig' [having more than one sense], 'undeutig' [without meaning], 'eindeutig' [having one meaning], 'mehrdeutig' [having more than one meaning] (pp. 48 ff. and 69),2 and unclarity indeed there is, but even the distinctions Husserl draws are inadequate. It was hardly to be expected that Schroder's use of the particles 'sinnig' and 'deutig' would not differ from my own; still less can I take issue with him over this, since when his work uppeared nothing had been published by me in this connection. For him this distinction is connected with that between common names and proper names, and the unclarity springs from a faulty conception of the distinction between concept and object. According to him there is nothing amiss with common names that are mehrdeutig, they are this when more than. one
? It is true that I had not then settled upon my present use of the words 'sense' and 'meaning', so that sometimes I said 'sense' where I should now say 'meaning'.
1 In what follows Frege is referring to the review of Schroder's Vorlesungen iiber die Algebra der Logik (Exakte Logik) I (Leipzig 1890), which Husserl had written for the Gottingischen Gelehrten Anzeigen (pp. 243-278, April 1891) (ed. ).
2 In the place referred to by Frege Schroder fixes on the adjectives ending in 'deutig' as terms for the sizes of extensions of concepts. Schroder speaks generally of names and calls proper names 'eindeutig', common names like 'my hand' 'zweideutig' [having two meanings], common names in general 'mehrdeutig' or 'vieldeutig' [having many meanings]. The corresponding formations with 'sinnig' are employed by Schroder to distinguish terms whose use is precisely fixed {'einsinnig' or 'univocal'), from terms with multiple meanings ('doppelsinnig' ! having a double sense], 'mehrsinnig' or 'equivocal') and from formations without sense ('unsinnig'; 'round square' in Schroder's example). With Husserl Frege chiefly criticizes Schroder for calling a name like 'round square' 'undeutig' when for this label to apply the? name is surely already presupposed as being significant as Much, so that it cannot at the same time be designated as 'unsinnlg' (ed. ).
? ? ? 124 [Comments on Sense and Meaning]
object falls under the corresponding concept. * On this view it would be possible for a common name to be undeutig too, like 'the round square', without its being defective. Schroder, however, calls it unsinnig as well and is thus untrue to his own way of speaking; for according to this the 'round square' would have to be called einsinnig, and Husserl was right when he called it a univocal common name; for 'univocal' and 'equivocal' correspond to Schroder's 'einsinnig' and 'mehrsinnii. Husserl says (p. 250) 'Obviously he confuses two quite different questions here, namely (1) whether a name has a Bedeutung (a 'Sinn'); and (2) whether there does or does not exist an object corresponding to the name'. This distinction is inadequate. The word 'common name' leads to the mistaken assumption that a common name is related to objects in essentially the same way as is a proper name, the difference being only that the latter names just one thing whilst the former is usually applicable to more than one. But this is false, and that is why I prefer 'concept-word' to 'common name'. A proper name must at least have a sense (as I use the word); otherwise it would be an empty sequence of sounds and it would be wrong to call it a name. But if it is to have a use in science we must require that it have a meaning too, that it designates or names an object. Thus it is via a sense, and only via a sense that a proper name is related to an object. 1 _
A concept-word must have a sense too and if it is to have a use in science, a meaning; but this consists neither of one object nor of a plurality of objects: it is a concept. Now in the case of a concept it can of course again be asked whether one object falls under it, or more than one or none. But
this relates directly to the concept and nothing else. So a concept-word can be absolutely impeccable, logically speaking, without there being an object to which it is related through its sense and meaning (the concept itself). As we see, this relation to an object is more indirect and inessential, so that there seems little point in dividing concept-words up according as no object falls under the corresponding concepts or one object or more than one.
* If, as Husserl says in the first footnote to p. 252, a distributive name is one 'whose Bedeutung is such that it designates any one of a plurality of things', then a concept-word (common name) is at any rate not a distributive name.
1 Since Schroder and Husserl did not distinguish, in the way Frege did, between the Sinn and Bedeutung of an expression, we have thought it best in this paragraph to preserve the actual German where these terms or (more commonly) their cognates with 'sinnig' and 'deutig' occur in quotation from these authors, or where Frege himself uses the latter in alluding to their views. We have given what help we could to the reader by providing renderings in square brackets; he should only remember not to attribute to the words 'sense' and 'meaning', as they occur in these renderings, the significance they have in the main body of the text, where they are of course used to render Frege's 'Sinn' and 'Bedeutung' (trans. ).
? [Comments on Sense and Meaning] 125
Logic must demand not only of proper names but of concept-words as well that the step from the word to the sense and from the sense to the meaning be determinate beyond any doubt. Otherwise we should not be entitled to speak of a meaning at all. Of course this holds for all signs and combinations of signs with the same function as proper names or concept- words.
? ? [128]
[129]
[129] [130] [131]
[131f. ]
Logic 1 [1897]
The word 'true' specifies the goal. Logic is concerned with the predicate 'true' in a special way. The word 'true' characterizes logic. True cannot be defined; we cannot say: an idea is true if it agrees with reality.
True primitive and simple. This feature of our predicate is to be brought out by comparing it with others. Predicating it is always included in predicating anything whatever. To locate the domain of application of the predicate 'true'. Not applicable to what is material. It is most frequently ascribed to sentences-but only to assertoric sentences. Not, however, to sentences as series of sounds.
Translation.
We do not need to consider mock assertions in logic.
The sense of a sentence is called a thought. The predicate 'true' applies to thoughts. Does it also apply to ideas? Even where an idea is called true, it is really a thought to which this predicate is ascribed. A thought is not an idea and is not composed of ideas. Thoughts and ideas are fundamentally different. By associating ideas we never arrive at anything that could be true.
The proper means of expression for a thought is a sentence. On the other hand, a sentence is hardly an appropriate vehicle for conveying ideas. By contrast, pictures and musical compositions are unsuited
for expressing thoughts. The predicate 'true' compared with 'beautiful'. The latter admits of degree, not the former. What is beautiful is beautiful only for him who experiences it as such. There is no disputing tastes. What is true is true in itself; nothing is beautiful in itself. The assumption of a normal human being always underlies objective judgements of beauty. However, what is normal?
The objective sense of 'beautiful' can only be based on the subjective sense. Nor is it of any use to replace the assumption of a normal human being by that of an ideal one. A work of art is a structure of ideas within us. Each of us has his own. Aesthetic judgements don't contradict one another. Anyone who asserts that it -is only our recognizing a thing as true that makes it so, would, by so doing, contradict the content of his own assertion. In reality he could assert
[132f. ]
1 The date mentioned on p. 147 and the quotation on p. J58 make it probable that this essay was composed in 1897 (ed. ). '
? Logic 127
nothing. Every opinion would then be unjustified; there would be no science. Properly speaking, there would be nothing that is true. The independence of being recognized by us is integral to the sense of the word 'true'. Nor do thoughts have to be thought by us in order to be true. Laws of nature are discovered (not invented).
l133f. ) Thoughts are independent of our thinking. A thought does not belong specially to the person who thinks it, as an idea does to the person who has it: whoever thinks it encounters it in the same way, as the same thought. Otherwise two people would never attach the same thought to the same sentence. A contradiction between the assertions of different people would be impossible. A dispute about the truth of something would be futile. There would be no common ground to fight on. As each man makes a judgement about his poem, if the
judgement is an aesthetic one, so each man would make a judgement about his thought, if the thought were related to a sentence as the auditory ideas of the spoken sounds are related to the sound waves. If a thought were something mental, then its truth could only consist in a relation to something external, and that this relation obtained would be a thought into the truth of which we could inquire.
l134f. ) Treadmill. A thought is something impersonal. Writing on a wall. Objection: what of a sentence like 'I am cold'? The spoken word often needs to be supplemented. The word 'I' does not always designate the same person. A sentence containing 'I' can be cast into a more appropriate form. Interjections are different. The words 'now' and 'here' analogous to 'I'. Identity of the speaker essential where a subjective judgement of taste is concerned.
[135) Objection:myuseoftheword'thought'isoutoftheordinary. 1136] Footnote. Dedekind's way of using it agrees with mine.
[137) Thoughts are not generated by, but grasped by, thinking.
l137f. ) A thought not something spatial, material. Only in a special sense is it something actual.
[138) False thoughts are also independent of the speaker. The predicate 'true' is predicated in predicating anything. In an assertoric sentence the expression of a thought and the recognition of its truth usually go hand in hand. This does not have to be so. An assertoric sentence does not always contain an assertion. Grasping a thought usually precedes the recognition of truth.
the distinction between concept and object. We see to begin with that in the expression 'There is at least one square root of 4', 'square root of 4' is being used predicatively: 'there is something that is a square root of 4'. In place of this we could say 'there is something that has the property of giving the result 4 when multiplied by itself. Hence what is here asser-
* In my Grundlagen I called such a concept a second order concept; in my Funktion und Begriff I called it a second level concept, as I shall do here.
? proper name can never be a pre- dicative expression, though it can be partofone. Idonotwanttosayitis false to assert about an object what is here asserted about a concept; I want to say it is impossible, sense- less, to do so.
The sentence 'there is Julius Caesar' is neither true nor false but senseless; the sentence 'there is a man whose name is Julius Caesar' has a sense, but here again we have a concept, as the indefinite article shows. We get the same thing in the sentence 'there is only one Vienna'. We must not let ourselves be deceived because language often uses the same word now as a proper name, now as a concept-word; in our example, the numeral indicates that we have the latter; 'Vienna' is here a concept-word, like ? metropolis'. Using it in this sense, we may say: 'Trieste is no Vienna'. If, on the other hand, we substitute 1201] 'Julius Caesar' for the proper name formed by the first six words of the sentence 'the concept square root of 4 is realized', we get a sentence that has a sense but is false; for the assertion that some- thing is realized (as the word is being taken here) can be truly made only about a quite special kind of objects, viz. such as can be designated by proper names of the form 'the concept F'. Thus the words 'the concept square root of 4' have an
ted of a concept can never be asserted of an object. This is not to saythatitisfalsetodothis,butim- possible: a sentence which tried to express such a thing would be absolutely devoid of sense; for it has no sense to use the name of an object predicatively. We have seen that even where the form of a sentence makes it look as if this is being done, the truth is that the object forms only part of what is asserted, since 'nothing other than' has to be added in thought. A sentence such as 'There is at least Julius Caesar' is senseless, although the sentence 'There is at least one man whose name is "Julius Caesar"' has a sense; but here again we have a concept, as the 'one' shows.
On Concept and Object 109
If, on the other hand, we sub- stitute the proper name 'Julius Caesar' for the proper name formed by the first six words of the sentence 'The concept square root of 4 is realized', we get a sentence that has a sense but is false; for the assertion that something is realized, as the word is meant here, is one we can only truly make of such objects as stand in a quite special relation to a concept. Thus the words 'the con- cept square root of 4' have an essentially different behaviour, as
? 110 On Concept and Object
essentially different behaviour, as regards possible substitutions, from the words 'square root of 4' in our original sentence; i. e. the reference of the two phrases is essentially
different.
What has been shown here in one
example holds good generally; the behaviour of the concept is essen- tially predicative, even where some- thing is being asserted about it; consequently it can be replaced there only by another concept, never by an object. Thus the assertion that is made about a concept does not suit an object. Second-level con- cepts, which concepts fall under, are essentially different from first-level concepts, which objects fall under.
regards possible substitutions, from the words 'square root of 4' in our original sentence; i. e. the meanings of the two properties are different, thoughrelated.
What has been shown here in one example holds good generally: the behaviour of the concept is essen- tially predicative even when some- thing is being asserted of it; conse- quently it can be replaced there only by another concept, never by an object; i. e. the assertion that is made about a concept does not fit an object at all. Moreover a concept (of second level) under which a concept falls is essentially different from a concept (of first level) under which objects fall.
In the sentence 'There is at least one square root of 4' we assert that the first level concept square root of 4 falls under a concept of second level, whereas in the sentence 'The concept square root o f 4 is realized' we assert that the object the concept square root of4 falls under the first level concept concept that is realized. We do indeed have the same thought in the two concepts, [sic. ] but this, being analysed dif- ferently, is construed in a different way.
The relation of an object to a concept that it falls under is dif- ferent from the admittedly similar relation of a concept to a concept (of second level). From now on we shall give parallel expression to the similarity and the difference by saying than an object falls under a concept, and a concept falls within a concept (of second level); for, strictly speaking, we have been making a mistake in using the same
The relation of an object to a first-level concept that it falls under is different from the (admittedly similar) relation of a first-level to a second-level concept. (To do justice at once to the distinction and to the similarity, we might perhaps say: An object falls under a first-level concept; a concept falls within a second-level concept. ) The dis- tinction of concept and object thus still holds, with all its sharpness.
? With this there hangs together what I have said (Grund/agen, ? 53) about my usage of the words 'property' and 'mark'; Kerry's dis- cussion gives me occasion to revert once more to this.
The words serve to signify relations, in sentences like ? (/J is a property of T' and '(/J is a mark of il'. In my way of speaking a thing can at once be a property and a mark but not of the same
thing.
words to cover both cases. From this we can see that the distinction between object and concept still holds in all its sharpness.
Connected with this is another distinction, namely that between property and characteristic mark. I have already explained this in ? 53 of my Grundlagen and at the time I thought I had made it sufficiently clear. Since, however, Kerry makes no use of it and falls into error as a result, I can only assume, alas, that he has not understood me; this time I will try to be more successful.
The words 'property' and 'characteristic mark' serve to designate relations such that something can at the same time be a property of r and a characteristic mark of L1. We express ourselves more precisely if we use the words 'characteristic mark' only in the phrase 'characteristic mark of a concept'. If a thing is a property of an object, then it is a characteristic mark of a first level concept. We may also speak of properties of a first level concept, and these will then be characteristic marks of second level concepts. I will call the concepts under which an object falls its properties.
If the object r has the properties (/J, X and '1', I may combine them into n; so that it is the same thing if I say that r has the property n, or, that r has the property (/J and r has the property X and r has the property '1'. I then call (/J, X, and 'I' marks of the concept n, and, at the same time, properties of r. It is clear that the relations of (/J to r and to n are
I call the concepts under which an object falls its properties; thus 'to be (/J is a property of T' is just another way of saying: 'T falls under the concept of a (/J'. If the object r has the properties (/), X, and '1', I may combine them into n; so that it is the same thing if I say that r has the [202] property n, or, that r has the properties (/), X, and '1'. I then call (/J, X, and 'I' marks of the concept n, and, at the same time, properties of r. It is clear that the relations of (/J to r and to n are quite different, and that conse-
On Concept and Object Ill
? 112 On Concept and Object
quently different terms are required. quite different; r falls under the r falls under the concept f/J; but n, concept f/J; but n, which is itself a which is itself a concept, cannot fall concept, cannot fall under the first under the first-level concept f/J; only level concept f/J; only to a second to a second-level concept could it level concept could it stand in a
stand in a similar relation. n is, on the other hand, subordinate to f/J.
Let us consider an example. Instead of saying:
'2 is a positive number' and '2 is a whole number' and '2 is less than 10'.
we may also say
'2 is a positive whole number less than 10'.
Here
appear as properties of the object 2, and also as marks of the concept
positive whole number less than 10.
This is neither positive, nor a whole number, nor less than 10. It is indeed subordinate to the concept whole number , b u t d o e s n o t fall under it.
Let us now compare with this what Kerry says in his second article (p. 424). 'By the number 4 we understand the result of additively combining 3 and 1. The concept object here occurring is the numerical individual 4; a quite definite number in the natural number-series. This object obviously bears just the marks that are named in its concept, and no others besides-provided we refrain, as we
similar relation.
to be a positive number, to be a whole number, to be less than 10,
? ? surely must, from counting as propria of the object its infinitely numerous relations to all other individual numbers; "the" number 4 is likewise the result of additively combining 3 and 1. '
We see at once that my dis- tinction between property and mark is here quite slurred over. Kerry distinguishes here between the num- ber 4 and 'the' number 4. I must confess that this distinction is in- comprehensible to me. The number 4 is to be a concept; 'the' number 4 is to be a concept-object, and none other than the numerical individual 4. It needs no proof that what we have here [203] is not my distinction between concept and object. I t almost looks as though what was floating (though very obscurely) before Kerry's mind were my dis- tinction between the sense and the reference of the words 'the number 4'. * But it is only of the reference of the words that we can say: this is the result of additively combining 3 and 1.
Again, how are we to take the word 'is' in the sentences 'the num- ber 4 is the result of additively combining 3 and I' and '"the" number 4 is the result of additively combining 3 and I'? Is it a mere copula, or does it help to express a logical equation? In the first case, 'the' would have to be left out before 'result', and the sentences would go like this:
'The number 4 is a result of addi- tively combining 3 and I';
* Cf. my essay 'On Sense and Reference' (cited above).
On Concept and Object 113
? 114 On Concept and Object '"The" number 4 is a result of
additively combining 3 and 1. "
In that case, the objects that Kerry designates by
'the number 4' and "'the" number 4' would both fall under the concept result o f additively combining 3
and 1.
And then the only question would be what difference there was be- tween these objects. (I am here using the words 'object' and 'concept' in my accustomed way. ) I should express as follows what Kerry is apparently trying to say:
'The number 4 has those properties, and those alone, which are marks of the concept: result ofadditively combining 3 and 1. '
I should then express as follows the sense of the first of our two sen- tences:
'To be a number 4 is the same as being a result of additive com- bination of 3 and 1. '
In that case, what I conjectured just now to have been Kerry's intention could also be put thus:
'The number 4 has those properties, and those alone, which are marks of the concept a number 4. '
[204] (We need not here decide whether this is true. ) The inverted commas around the definite article in the words '"the" number 4' could in that case be omitted.
But in these attempted in- terpretations we have assumed that in at least one of the two sentences the definite articles in front of 'result'
? and 'number 4' were inserted only by an oversight. It we take the words as they stand, we can only regard them as having the sense of a logical equation, like:
'The number 4 is none other than the result of additively combining 3 and 1. '
The definite article in front of 'result' is here logically justified only if it is known (i) that there is such a result; (ii) that there is not more than one. In that case, the phrase designates an object, and is to be regarded as a proper name. If both of our sen- tences were to be regarded as logical equations, then, since their right sides are identical, it would follow from them that the number 4 is 'the' number 4, or, if you prefer, that the number 4 is no other than 'the' number 4; and so Kerry's dis- tinction would have been proved untenable. However, it is not my present task to point out contra- dictions in his exposition; his way of taking the words 'object' and 'con- cept' is not properly my concern here. I am only trying to set my own usage of these words in a clearer light, and incidentally show that in any case it differs from his, whether that is consistent or not.
I do not at all dispute Kerry's right to use the words 'concept' and 'object' in his own way, if only he would respect my equal right, and admit that with my use of terms I have got hold of a distinction of the highest importance. I admit that there is a quite peculiar obstacle in the way of an understanding with my reader. By a kind of necessity of language, my expressions, taken
On Concept and Object
115
? 116
On Concept and Object
literally, sometimes miss my thought; I mention an object, when what I intend is a concept. I fully realize that in such cases I was relying upon a reader who would be ready to meet me half-way-who does not begrudge a pinch of salt.
Somebody may think that this is an artificially created difficulty; that there is no need at all to take account of such an unmanageable thing as what I call a concept; that one might, like Kerry, regard an object's falling under a concept as a relation, in which the same thing could occur now as object, now as concept. [205] The words 'object' and 'concept' would then serve only to indicate the different positions in the relation. This may be done; but anybody who thinks the difficulty is avoided this way is very much mistaken; it is only shifted. For not all the parts of a thought can be complete; at least one must be 'un- saturated', or predicative; otherwise they would not hold together. For example, the sense of the phrase 'the number 2' does not hold together with that of the expression 'the concept prime number' without a link. We apply such a link in the sentence 'the number 2 falls under the concept prime number'; it is contained in the words 'falls under', which need to be completed in two ways-by a subject and an ac- cusative; and only because their sense is thus 'unsaturated' are they capable of serving as a link. Only when they have been supplemented in this twofold respect do we get a complete sense, a thought. I say that such words or phrases stand for a relation. We now get the same
? difficulty for the relation that we were trying to avoid for the concept. For the words 'the relation of an object to the concept it falls under' designate not a relation but an object; and the three proper names 'the number 2', 'the concept prime number', 'the relation of an object to a concept it falls under', hold aloof from one another just as much as the first two do by themselves; however we put them together, we get no sentence. It is thus easy for us to see that the difficulty arising from the 'unsaturatedness' of one part of the thought can indeed be shifted, but not avoided. 'Complete' and 'un- saturated' are of course only figures of speech; but all that I wish or am able to do here is to give hints.
It may make it easier to come to un understanding if the reader com- pares my work Function und BegrifJ. For over the question what it is that is called a function in Analysis, we come up against the same obstacle; and on thorough investigation it will be found that the obstacle is essential, and founded on the nature of our language; that we cannot avoid a certain inap- propriateness of linguistic ex- pression; and that there is nothing for it but to realize this and always take it into account.
On Concept and Object 117
? ? [Comments on Sense and Meaning] 1 [1892-1895]
In an article (Uber Sinn und Bedeutung) I distinguished between sense and meaning in the first instance only for the case of proper names (or, if one prefers, singular terms). The same distinction can also be drawn for concept? words. Now it is easy to become unclear about this by confounding the division into concepts and objects with the distinction between sense and meaning, so that we run together sense and concept on the one hand and meaning and object on the other. To every concept-word or proper name, there corresponds as a rule a sense and a meaning, as I use these words. Of course in fiction words only have a sense, but in science and wherever we are concerned about truth, we are not prepared to rest content with the sense, we also attach a meaning to proper names and concept-words; and if through some oversight, say, we fail to do this, then we are making a mistake that can easily vitiate our thinking. The meaning of a proper name is the object it designates or names. A concept-word means a concept, if the word is used as is appropriate for logic. I may clarify this by drawina attention to a fact that seems to weigh heavily on the side of extensionalist as against intensionalist logicians: namely, that in any sentence we can substitute salva veritate one concept-word for another if they have the same extension, so that it is also the case that in relation to inference, and where the laws of logic are concerned, that concepts differ only in so far as their extensions are different. The fundamental logical relation is that of an object's falling under a concept: all relations between concepts can be reduced to this. If an object falls under a concept, it falls under all concepti with the same extension, and this implies what we said above. Therefore just as proper names can replace one another salva veritate, so too can concept? words, if their extension is the same. Of course the thought will alter when such replacements are made, but this is the sense of the sentence, not ita meaning. * The meaning, which is the truth-value, remains the same. For thia reason we might easily come to propose the extension of a concept as the
* Cf. my article Uber Sinn und Bedeutung.
1 These comments were not composed before 1892, the year in which the article Ober Sinn und Bedeutung appeared. They are part of a bundle of papers entitled 'Schrodersche Logik', which existed in a complete form prior to the destruction of the NachlajJ. The first part of these constituted a draft of Frege's article Kritischl Beleuchtung einiges Punkte in E. Schroder's Vorlesungen iiber die Algebra der
Logik (ed. ).
? [Comments on Sense and Meaning] 119
meaning of a concept-word; to do this, however, would be to overlook the fact that the extensions of concepts are objects and not concepts (Cf. my essay Funktion und Begrifl). Nevertheless there is a kernel of truth in this position. In order to bring it out, I need to advert to what I said in my mono- graph on Funktion und Begriff. On the view expressed there a concept is a function of one argument, whose value is always a truth-value. Here I am borrowing the term 'function' from Analysis and, whilst retaining what is essential to it, using it in a somewhat extended meaning, a procedure for which the history of Analysis itself affords a precedent. The name of a func- tion is accompanied by empty places (at least one) where the argument is to go; this is usually indicated by the letter 'x' which fills the empty places in 4uestion. But the argument is not to be counted as belonging to the function, und so the letter 'x' is not to be counted as belonging to the name of the function either. Consequently one can always speak of the name of a function as having empty places, since what fills them does not, strictly speaking, belong to them. Accordingly I call the function itself unsaturated, or in need of supplementation, because its name has first to be completed with the sign of an argument if we are to obtain a meaning that is complete in itself. I call such a meaning an object and, in this case, the value of the function for the argument that effects the supplementing or saturating. In the cases we first encounter the argument is itself an object, and it is to these that we shall mainly confine ourselves here. Now with a concept we have the special case that the value is always a truth-value. That is to say, if we complete the name of a concept with a proper name, we obtain a sentence whose sense is a thought; and this sentence has a truth value as its meaning. To acknowledge this meaning as that of the True (as the True) is to judge that the object which is taken as the argument falls under the concept. What in the case of a function is called unsaturatedness, we may, in the case of a concept, call its predicative nature. ? This comes out even in the cases in which we speak of a subject-concept ('All equilateral triangles are equiangular' means 'If anything is an equilateral triangle, then it is an equiangular triangle').
Such being the essence of a concept, there is now a great obstacle in the way of expressing ourselves correctly and making ourselves understood. If I want to speak of a concept, language, with an almost irresistible force, compels me to use an inappropriate expression which obscures-! might nlmost say falsities-the thought. One would assume, on the basis of its 1malogy with other expressions, that if I say 'the concept equilateral triangle' I am designating a concept, just as I am of course naming a planet If I say 'the planet Nepture'. But this is not the case; for we do not have anything with a predicative nature. Hence the meaning of the expression 'the
? The words 'unsaturated' and 'predicative' seem more suited to the sense than the meaning; still there must be something on the part of the meaning which corresponds to this, and I know of no better words.
Cf. Wundt's Logik.
? 120 [Comments on Sense and Meaning]
concept equilateral triangle' (if there is one in this case) is an object. We cannot avoid words like 'the concept', but where we use them we must always bear their inappropriateness in mind. ? From what we have said it follows that objects and concepts are fundamentally different and cannot stand in for one another. And the same goes for the corresponding words or signs. Proper names cannot really be used as predicates. Where they might seem to be, we find on looking more closely that the sense is such that they only form part of the predicate: concepts cannot stand in the same relations as objects. It would not be false, but impossible to think of them as doing so. Hence, the words 'relation of a subject to a predicate' designate two quite different relations, according as the subject is an object or is itself a concept. Therefore it would be best to banish the words 'subject' and 'predicate' from logic entirely, since they lead us again and again to confound two quite different relations: that of an object's falling under a concept and that of one concept being subordinated to another. The words 'all' and 'some', which go with the grammatical subject, belong in sense with the grammatical predicate, as we see if we go over to the negative (not all, nonnulli}. From this alone it immediately follows that the predicate in these cases is different from that which is asserted of an object. And in the same way the relation of equality, by which I understand complete coincidence, identity, can only be thought of as holding for objects, not concepts. If we say 'The meaning of the word "conic section" is the same as that of the concept-word "curve of the second degree"' or 'The concept conic section coincides with the concept curve o f the second degree', the words 'meaning of the concept-word "conic section"' are the name of an object, not of a concept; for their nature is not predicative, they are not unsaturated, they cannot be used with the indefinite article. The same goes for the words 'the concept conic section'. But although the relation of equality can only be thought of as holding for objects, there is an analogous relation for concepts.
Since this is a relation between concepts I call it a second level relation, whereas the former relation I call a first level relation. We say that an object a is equal to an object b (in the sense of completely coinciding with it) if a falls under every concept under which b falls, and conversely. We obtain something corres- ponding to this for concepts if we switch the roles of concept and object. We could then say that the relation we had in mind above holds between the concept ([> and the concept X, if every object that falls under ([> also falls under X, and conversely. Of course in saying this we have again been unable
to avoid using the expressions 'the concept ([>','the concept X', which again obscures the real sense. So for the reader who is not frightened of the concept-script I will add the following: The unsaturatedness of a concept (of first level) is represented in the concept-script by leaving at least one empty place in its designation where the name of the object which we are saying falls under the concept is to go. This place or places always has to be filled
? I shall deal with this difficulty.
? ? [Comments on Sense and Meaning] 121
in some way or other. Besides being filled by a proper name it can also be filled by a sign which only indicates an object. We can see from this that the sign of equality, or one analogous to it, can never be flanked by the designation of a concept alone, but in addition to the concept an object must also be designated or indicated as well. Even if we only indicate concepts schematically by a function-letter, we must see to it that we give expression to their unsaturatedness by an accompanying empty place as in C/>( ) and X( ). In other words, we may only use the letters (cl>, X}, which are meant to indicate or designate concepts, as function-letters, i. e. in such a way that they are accompanied by a place for the argument (the space between the following brackets). This being so, we may not write cp = X, because here the letters cp and X do not occur as function-letters. But nor may we write C/>( ) = X( }, because the argument-places have to be filled. But when they are filled, it is not the functions (concepts) themselves that are put equal to one another: in addition to the function-letter there will be something else on either side of the equality sign, something not belonging to the function.
These letters cannot be replaced by letters that are not used as function- letters: there must always be an argument-place to receive the 'd. The idea might occur to one simply to write cp = X. This may seem all right so long as we are indicating concepts schematically, but a mode of designation that is really adequate must provide for all cases. Let us take an example which I have already used in my paper on Funktion und Begriff.
For every argument the function x 2 = 1 has the same (truth-} value as the function (x + 1}2 = 2(x + 1) i. e. every object falling under the concept less by 1 than a number whose square is equal to its double falls under the concept square root of1 and conversely. If we expressed this thought in the
way that we gave above, 1 we should have
(al=1)~ ((a+1}2=2(a+1))
What we have here is that second level relation which corresponds to, but should not be confused with, equality (complete coincidence) between objects. If we write it-0-~(a2 = 1) = ((a + 1)2 = 2(a + 1}}, we have expressed what is essentially the same thought, construed as an equation between values of functions that holds generally. We have here the same second level relation; we have in addition the sign of equality, but this does not suffice on its own to designate this relation: it has to be used in combination with the sign for generality: in the first line we have a general statement but not an equation. In e(e2 = 1) = il((a + 1)2 = 2(a + 1}} we do have an equation, but not between concepts (which is impossible} but between objects, namely extensions of concepts.
Now we have seen that the relation of equality between objects cannot be
1 It may be that the notation used in the following formula, which Frege has not explained above, was introduced in the lost first part of the manuscript (see footnote lop. II8)(ed. ).
? ? 122 [Comments on Sense and Meaning]
conceived as holding between concepts too, but that there is a correspond- ing relation for concepts. It follows that the word 'the same' that is used to designate the former relation between objects cannot properly be used to designate the latter relation as well. If we try to use it to do this, the only recourse we really have is to say 'the concept ([> is the same as the concept X' and in saying this we have of course named a relation between objects,? where what is intended is a relation between concepts. We have the same case if we say 'the meaning of the concept-word A is the same as that of the concept word B'. Indeed we should really outlaw the expression 'the meaning of the concept-word A', because the definite article before 'meaning' points to an object and belies the predicative nature of a concept. It would be better to confine ourselves to saying 'what the concept word A means', for this at any rate is to be used predicatively: 'Jesus is, what the concept word "man" means' in the sense of 'Jesus is a man'.
Now if we bear all this in mind, we shall be well able to assert 'what two concept-words mean is the same if and only if the extensions of the corresponding concepts coincide' without being led astray by the improper use of the word 'the same'. And with this statement we have, I believe, made an important concession to the extensionalist logicians. They are right when they show by their preference for the extension, as against the intension, of a concept that they regard the meaning and not the sense of words as the essential thing for logic. The intensionalist logicians are only too happy not to go beyond the sense; for what they call the intension, if it is not an idea, is nothing other than the sense. They forget that logic is not concerned with how thoughts, regardless of truth-value, follow from thoughts, that the step from thought to truth-value-more generally, the step from sense to meaning-has to be taken. They forget that the laws of logic are first and foremost laws in the realm of meanings and only relate indirectly to sense. If it is a question of the truth of something-and truth is the goal of logic-we also have to inquire after meanings; we have to throw aside proper names that do not designate or name an object, though they may have a sense; we have to throw aside concept-words that do not have a meaning. These are not such as, say, contain a contradiction-for there is nothing at all wrong in a concept's being empty-but such as have vague boundaries. It must be determinate for every object whether it falls under a concept or not; a concept word which does not meet this requirement on its meaning is
meaningless. E. g. the word 'wiJ). v' (Homer, Odyssey X, 305) belongs to this class, although it is true that certain characteristic marks are supplied. For this reason the context cited need not lack a sense, any more than other contexts in which the name 'Nausicaa', which probably does not mean or name anything, occurs. But it behaves as if it names a girl, and it is thus assured of a sense. And for fiction the sense is enough. The tkought, though it is devoid of meaning, of truth-value, is enough, but not for science.
? These objects have the names 'the concept ([>'and 'the concept X'.
? ? ? [Comments on Sense and Meaning] 123
In my Grundlagen and the paper Uber formale Theorien der Arithmetik I showed that for certain proofs it is far from being a matter of indifference whether a combination of signs--e. g. F l - h a s a meaning* or not, that, on the contrary, the whole cogency of the proof stands or falls with this. The meaning is thus shown at every point to be the essential thing for science. Therefore even if we concede to the intensionalist logicians that it is the concept as opposed to the extension that is the fundamental thing, this does not mean that it is to be taken as the sense of a concept-word: it is its meaning, and the extensionalist logicians come closer to the truth in so far us they are presenting-in the extension-a meaning as the essential thing. Though this meaning is certainly not the concept itself, it is still very closely connected with it.
1
Husserl takes Schr6der to task for the unclarity in his discussion of the words 'unsinnig' [without sense], 'einsinnig' [having one sense], and 'mehrsinnig' [having more than one sense], 'undeutig' [without meaning], 'eindeutig' [having one meaning], 'mehrdeutig' [having more than one meaning] (pp. 48 ff. and 69),2 and unclarity indeed there is, but even the distinctions Husserl draws are inadequate. It was hardly to be expected that Schroder's use of the particles 'sinnig' and 'deutig' would not differ from my own; still less can I take issue with him over this, since when his work uppeared nothing had been published by me in this connection. For him this distinction is connected with that between common names and proper names, and the unclarity springs from a faulty conception of the distinction between concept and object. According to him there is nothing amiss with common names that are mehrdeutig, they are this when more than. one
? It is true that I had not then settled upon my present use of the words 'sense' and 'meaning', so that sometimes I said 'sense' where I should now say 'meaning'.
1 In what follows Frege is referring to the review of Schroder's Vorlesungen iiber die Algebra der Logik (Exakte Logik) I (Leipzig 1890), which Husserl had written for the Gottingischen Gelehrten Anzeigen (pp. 243-278, April 1891) (ed. ).
2 In the place referred to by Frege Schroder fixes on the adjectives ending in 'deutig' as terms for the sizes of extensions of concepts. Schroder speaks generally of names and calls proper names 'eindeutig', common names like 'my hand' 'zweideutig' [having two meanings], common names in general 'mehrdeutig' or 'vieldeutig' [having many meanings]. The corresponding formations with 'sinnig' are employed by Schroder to distinguish terms whose use is precisely fixed {'einsinnig' or 'univocal'), from terms with multiple meanings ('doppelsinnig' ! having a double sense], 'mehrsinnig' or 'equivocal') and from formations without sense ('unsinnig'; 'round square' in Schroder's example). With Husserl Frege chiefly criticizes Schroder for calling a name like 'round square' 'undeutig' when for this label to apply the? name is surely already presupposed as being significant as Much, so that it cannot at the same time be designated as 'unsinnlg' (ed. ).
? ? ? 124 [Comments on Sense and Meaning]
object falls under the corresponding concept. * On this view it would be possible for a common name to be undeutig too, like 'the round square', without its being defective. Schroder, however, calls it unsinnig as well and is thus untrue to his own way of speaking; for according to this the 'round square' would have to be called einsinnig, and Husserl was right when he called it a univocal common name; for 'univocal' and 'equivocal' correspond to Schroder's 'einsinnig' and 'mehrsinnii. Husserl says (p. 250) 'Obviously he confuses two quite different questions here, namely (1) whether a name has a Bedeutung (a 'Sinn'); and (2) whether there does or does not exist an object corresponding to the name'. This distinction is inadequate. The word 'common name' leads to the mistaken assumption that a common name is related to objects in essentially the same way as is a proper name, the difference being only that the latter names just one thing whilst the former is usually applicable to more than one. But this is false, and that is why I prefer 'concept-word' to 'common name'. A proper name must at least have a sense (as I use the word); otherwise it would be an empty sequence of sounds and it would be wrong to call it a name. But if it is to have a use in science we must require that it have a meaning too, that it designates or names an object. Thus it is via a sense, and only via a sense that a proper name is related to an object. 1 _
A concept-word must have a sense too and if it is to have a use in science, a meaning; but this consists neither of one object nor of a plurality of objects: it is a concept. Now in the case of a concept it can of course again be asked whether one object falls under it, or more than one or none. But
this relates directly to the concept and nothing else. So a concept-word can be absolutely impeccable, logically speaking, without there being an object to which it is related through its sense and meaning (the concept itself). As we see, this relation to an object is more indirect and inessential, so that there seems little point in dividing concept-words up according as no object falls under the corresponding concepts or one object or more than one.
* If, as Husserl says in the first footnote to p. 252, a distributive name is one 'whose Bedeutung is such that it designates any one of a plurality of things', then a concept-word (common name) is at any rate not a distributive name.
1 Since Schroder and Husserl did not distinguish, in the way Frege did, between the Sinn and Bedeutung of an expression, we have thought it best in this paragraph to preserve the actual German where these terms or (more commonly) their cognates with 'sinnig' and 'deutig' occur in quotation from these authors, or where Frege himself uses the latter in alluding to their views. We have given what help we could to the reader by providing renderings in square brackets; he should only remember not to attribute to the words 'sense' and 'meaning', as they occur in these renderings, the significance they have in the main body of the text, where they are of course used to render Frege's 'Sinn' and 'Bedeutung' (trans. ).
? [Comments on Sense and Meaning] 125
Logic must demand not only of proper names but of concept-words as well that the step from the word to the sense and from the sense to the meaning be determinate beyond any doubt. Otherwise we should not be entitled to speak of a meaning at all. Of course this holds for all signs and combinations of signs with the same function as proper names or concept- words.
? ? [128]
[129]
[129] [130] [131]
[131f. ]
Logic 1 [1897]
The word 'true' specifies the goal. Logic is concerned with the predicate 'true' in a special way. The word 'true' characterizes logic. True cannot be defined; we cannot say: an idea is true if it agrees with reality.
True primitive and simple. This feature of our predicate is to be brought out by comparing it with others. Predicating it is always included in predicating anything whatever. To locate the domain of application of the predicate 'true'. Not applicable to what is material. It is most frequently ascribed to sentences-but only to assertoric sentences. Not, however, to sentences as series of sounds.
Translation.
We do not need to consider mock assertions in logic.
The sense of a sentence is called a thought. The predicate 'true' applies to thoughts. Does it also apply to ideas? Even where an idea is called true, it is really a thought to which this predicate is ascribed. A thought is not an idea and is not composed of ideas. Thoughts and ideas are fundamentally different. By associating ideas we never arrive at anything that could be true.
The proper means of expression for a thought is a sentence. On the other hand, a sentence is hardly an appropriate vehicle for conveying ideas. By contrast, pictures and musical compositions are unsuited
for expressing thoughts. The predicate 'true' compared with 'beautiful'. The latter admits of degree, not the former. What is beautiful is beautiful only for him who experiences it as such. There is no disputing tastes. What is true is true in itself; nothing is beautiful in itself. The assumption of a normal human being always underlies objective judgements of beauty. However, what is normal?
The objective sense of 'beautiful' can only be based on the subjective sense. Nor is it of any use to replace the assumption of a normal human being by that of an ideal one. A work of art is a structure of ideas within us. Each of us has his own. Aesthetic judgements don't contradict one another. Anyone who asserts that it -is only our recognizing a thing as true that makes it so, would, by so doing, contradict the content of his own assertion. In reality he could assert
[132f. ]
1 The date mentioned on p. 147 and the quotation on p. J58 make it probable that this essay was composed in 1897 (ed. ). '
? Logic 127
nothing. Every opinion would then be unjustified; there would be no science. Properly speaking, there would be nothing that is true. The independence of being recognized by us is integral to the sense of the word 'true'. Nor do thoughts have to be thought by us in order to be true. Laws of nature are discovered (not invented).
l133f. ) Thoughts are independent of our thinking. A thought does not belong specially to the person who thinks it, as an idea does to the person who has it: whoever thinks it encounters it in the same way, as the same thought. Otherwise two people would never attach the same thought to the same sentence. A contradiction between the assertions of different people would be impossible. A dispute about the truth of something would be futile. There would be no common ground to fight on. As each man makes a judgement about his poem, if the
judgement is an aesthetic one, so each man would make a judgement about his thought, if the thought were related to a sentence as the auditory ideas of the spoken sounds are related to the sound waves. If a thought were something mental, then its truth could only consist in a relation to something external, and that this relation obtained would be a thought into the truth of which we could inquire.
l134f. ) Treadmill. A thought is something impersonal. Writing on a wall. Objection: what of a sentence like 'I am cold'? The spoken word often needs to be supplemented. The word 'I' does not always designate the same person. A sentence containing 'I' can be cast into a more appropriate form. Interjections are different. The words 'now' and 'here' analogous to 'I'. Identity of the speaker essential where a subjective judgement of taste is concerned.
[135) Objection:myuseoftheword'thought'isoutoftheordinary. 1136] Footnote. Dedekind's way of using it agrees with mine.
[137) Thoughts are not generated by, but grasped by, thinking.
l137f. ) A thought not something spatial, material. Only in a special sense is it something actual.
[138) False thoughts are also independent of the speaker. The predicate 'true' is predicated in predicating anything. In an assertoric sentence the expression of a thought and the recognition of its truth usually go hand in hand. This does not have to be so. An assertoric sentence does not always contain an assertion. Grasping a thought usually precedes the recognition of truth.
