The
pedagogical
views of Kattich are similar (1571- 1836).
Windelband - History of Philosophy
Arts, in Jour.
Spec.
Phil.
, Vols.
11 and 16, by Morris and Dewey Eng.
\x.
of prin.
works by F.
lwes, Bonn Lib.
, 1884, of the Ethics by White, Lond.
1883, and of Selections by Fullerton, NY.
1892.
]
Of philosophical writers in Germany who attached themselves to the train of the movement among the two civilised peoples of the West are to be mentioned Joachim Jung (1587-1667 Logica Hamburgiensis, 1638); cf. G. E. Guhrauer.
;
;
;
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;
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;
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;
;
;
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382 The Renaissance : Natural Science Period. [Part IV.
J. J. und sein Zeitalter (Stuttg. and Tfib. 1859); the Jena mathematician, Erhard VVeigel, the teacher of Leibniz and Puffendorf ; Walther von Tschirn- hausen (1661-1708 ; Medicina Mentis sive Artis Inveniendi Prcecepta Generalia, Amsterdam, 1087), and Samuel Puffendorf (1032-1694; under the pseudonym Severinus a Monzambano, De Statu Bei publico: Germanicce, 1667, German by H. Bresslau, Berlin, 1870 ; De Jure Naturae et Gentium, London, 1672).
Leibniz belongs in this period, not only in point of time, but also as regards the origination and the motives of his metaphysics, while with other interests of his incredibly many-sided nature, he ranges on into the age of the Enlighten ment ; cf. on this, Part V. Here, therefore, we have to consider principally his methodological and metaphysical writings : De Principio Individui, 1663 ; De Arte Combinatoria, 1666 ; Nova Methodus pro Maximis et Minimis, 1684 ; De Scientia Universali seu Calculo Philosophico, 1684 (cf. A. Trendelenburg, Hist. Beitrage zur Philos. , III. 1 ff. ); De Prima: Philosophies Emendatione, 1694; Systeme Nouveau de la Nature, 1695, with the three Eclaircissements connected with it, 1696 ; also the Monadologie, 1714, the Principes de la Nature et de la Grace, 1714, and a great part of his extended correspondence. Among the editions of his philosophical writings the excellent edition by J. E. Erdmann (^Berlin, 1840) has now been surpassed by that of C. J. Gerhardt (7 vols. , Ber lin, 1875-91). — On the system as a whole cf. L. Feuerbach, Darstellung, Ent- vricklnng und Kritik der Leibnizischen Philos. (Ansbach, 1837), A. Nourisson, La Philos. de L. (Paris, 1860); E. Wendt, Die Entwicklung der LSschen Mo- nadenlehre bis 1695 (Berlin, 1886). [E. Dillmann, Sine neue Darst. der L. 'schen Monadenlehre, Leips. 1891. See also the lit. on p. 444. ]
On the historical and systematic relation of the systems to one another : H. C. W. Sigwart, Ueber den Zusammenhang des Spinozismus mit der cartes. Philos. (Tub. 1816) and Die Leibniz'sche Lehre von der prastabilirten Harmonie in ihrem Zusammenhang mit fruheren Philosophemen (ib. 1822) ; C. Schaar- schmidt, Descartes und Spinoza (Bonn, 1860) ; A. Foucher de Careil, Leibniz, Descartes et Spinoza (Paris, 1863) ; E. Pfleiderer, L. und Geulincx (Tub. 1884); E. Zeller, Sitz. -Ber. d. Berliner Akad, 1884, pp. 673 ff. ; F. Tonnies, Leibniz und Hobbes in Philos. Monatsh; 1887, pp. 357 ft*. ; L. Stein, Leibniz und Spinoza (Berlin, 1890). [E. Caird, Art Cartesianism, in Enc. Brit. , reprinted in Vol. 2 of his Essays, Lond. and N. Y. 1892 ; Saisset's Modern Pantheism. ]
To the founders of the philosophy of law (cf. C. v. Kaltenborn, Die Vorlaufer des Hugo Grotius, Leips. 1848 ; and B. v. Mohl, Gesch. und Litteratur der Staatswissenschaften, Erlangen, 1866-68) belong Nicolo Macchiavelli (1469- 1627 ; H Principe, Discorsi sulla prima decade di Tito Livio ; [Works, tr. by C. E. Detmold, Boston, 1883. ] Thomas More (1480-1636 ; De Optimo Bei publico- Statu sive de Nova Insula Utopia, 1516) ; Jean Bodin (1530-1697) ; Six Livres de la Bipublique, 1577; an extract from the Heptaplomeres has been given by Guhrauer, Berlin, 1841) ; Albericus Oentilis (1551-1611 ; De Jure Belli, 1688) ; Johannes Althus (1557-1638 ; Politico, Groningen, 1610, cf. O. Gierke, Unters. z. deutsch. Staats- u. Bechtsgesch. , Breslau, 1880); Hugo de Groot (1583-1645 ; De Jure Belli et Pacis, 1646; cf. H. Luden, H. G. , Berlin, 1806).
Of the Protestants who treat of the philosophy of law may be named, be sides Melancthon, J. Oldendorf (Elementaris Introductio, 1539), Nic. Hemming
(De Lege Natural, 1562), Ben Winkler (Principia Juris, 1615) ; of the Catho lics besides Suarez, Rob. Bellarmin (1642-1621 ; De Potentate Pontijicis in
Temporalibus) and Mariana (1537-1624 ; De Bege et Begis Institutione).
Natural religion and natural morals in the seventeenth century found in England their main supporters in Herbert of Cnerbury (1581-1648 ; Tractatus de Veritate, 1624 ; De Beligione Gentilium Errorumque apud eos Causis, 1663 ; on him Ch. de Remusat, Paris, 1873), and Richard Cumberland (De Legibu* Natural Disquisitio Philosophica, Lond. 1672). Among the Platonists or Neo-
Platonists of England at the same time are prominent Ralph Cudworth (1617— 1688 ; The Intellectual System of the Universe, Lond. 1678, Latin, Jena, 1783) and Henry More (1614-1687 ; Encheiridion Metaphysicum. His correspondence with Descartes is printed in the latter's works, Vol. X. , Cousin's ed. ). [Pfcrt. of Cudworth, by C. E. Lowrey, with bibliog. , N. Y. 1884; Tulloch's Rational Theol. and Christian Phil, in Eng. in ^^th Cent. ] Theophilus Gale and his son, Thomas Gale, may be added to the authors above.
Chap. 2, $ 30. ] Problem of Method : Bacon. 383
§ 30. The Problem of Method.
All beginnings of modern philosophy have in common an impul sive opposition against "Scholasticism," and at the same time a naive lack of understanding for the common attitude of dependence upon some one of its traditions, which they nevertheless all occupy. This fundamental oppositional character brings with it the conse quence, that in all cases where it is not merely wants of the feelings, or fanciful views that are set over against the old doctrines, reflec tion on new methods of knowledge stands in the foreground. Out of the insight into the unfruitfulness of the " syllogism," which could merely set forth in proof or refutation that which was already known, or apply the same to a particular case, arises the demand for an ars inveniendi, a method of investigation, a sure way to the discovery of the new.
1. If now nothing was to be accomplished with the help of rhetoric, the nearest expedient was to attack the matter by the reverse method, proceeding from the particular, from the facts. This had been commended by Vives and Sanchez, and practised by Telesio and Campanella. But they had neither gained full confi dence in experience nor known afterwards how to make any right beginning with their facts. In both lines Bacon believed that he could point out new paths for science, and in this spirit he set up his " New Organon " as over against the Aristotelian.
Every -day perception — he confesses, admitting the well-known sceptical arguments — offers, indeed, no sure basis for a true knowl edge of Nature ; in order to become an experience that can be used by science it must first be purified from all the erroneous additions which have grown together with it in our involuntary way of regard ing things. These perversions or falsifications of pure experience Bacon calls idols, and presents his doctrine of these fallacious images in analog}' with the doctrine of the fallacious conclusions in the old dialectic. 1 There are first the "idols of the tribe" (idola tribus), the illusions that are given in connection with human nature in general, following which we are always suspecting an order and an end in things, making ourselves the measure of the outer world, blindly retaining a mode of thought which has once been excited by impressions, and the like; then the "idols of the cave" (idola specus), by reason of which every individual by his natural disposi tion, and his situation in life, finds himself shut into his cave;*
• Nov. Org. I. 39 fl.
* Bacon'* utrotigly rhetorical language, rich in imagery, aims by this term let Dt Auf/m. V. ch. 4) to recall Plato'* well-known parable of the Cave (Xtp-
384 The Renaissance : Natural Science Period. [Part IA .
then the "idols of the market" (idola fori), the errors which axe everywhere brought about by intercourse among men, especially by language, and by adherence to the word which we substitute for the idea; finally, the "idols of the theatre" (idola theatri), the illusory
of theories which we credulously receive from human history and repeat without subjecting them to any judgment of our own. In this connection Bacon finds opportunity to direct a most violent polemic against the word-wisdom of Scholasticism, against the rule of authority, against the anthropomorphism of earlier philosophy, and to demand a personal examination of things them selves, an unprejudiced reception of reality. Nevertheless he does not get beyond this demand ; for the statements as to how the mera experientia is to be gained and separated from the enveloping husks of the idols are extremely meagre, and while Bacon teaches that one must not limit himself to accidental perceptions, but must set about his observation methodically, and supplement ix bv experiment ' which he thinks out and makes for himself, this also is but a general designation of the task, and a theoretical insight into the essential nature of experiment is still wanting.
Quite similar is the case with the method of Induction, which Bacon proclaimed as the only correct mode of elaborating facts. With its aid we are to proceed to general cognitions (axioms), in order that we may ultimately from these explain other phenomena. In this activity the human mind, among whose constitutional errors is over-hasty generalisation, is to be restrained as much as possible; it is to ascend quite gradually the scale of the more general, up to the most general. Healthy and valuable as these prescriptions are, we are the more surprised to find that with Bacon their more de tailed carrying out is completed in conceptions and modes of view which are entirely scholastic*
All knowledge of Nature has for its end to understand the causes of things. Causes, however, are — according to the old Aristotelian scheme — formal, material, efficient, or final. Of these only the " formal " causes come into consideration ; for all that takes place has its grounds in the " Forms," in the " natures " of things. Hence when Bacon's Induction searches for the "Form" of phenomena, e. g. for the Form of heat, Form is here understood quite in the sense of Scotism as the abiding essence or nature of phenomena. The Form of that which is given in perception is composed out of
phantoms
614), which is the more unfortunate as, in the Platonic passage, it is precisely the general limited nature of knowledge by the senses that is dealt with.
> Nov. Org. I. 82.
1 Cf. the circumstantial exposition in the second book of the Nov. Org
Chap. 2, § 30. ] Problem of Method : Bacon. 385
simpler " Forms " and their " differences," and these it is important to discover. To this end as many cases as possible in which the phenomenon in question appears, are brought together into a tabula prvesentios, and in like manner, those in which the phenomenon is lacking are brought together into a tabula absentia;; to these is added, in the third place, a tabula graduum, in which the varying intensity with which the phenomenon appears is compared with the varying intensity of other phenomena. The problem is then to be solved by a progressive process of exclusion (exclusio). The Form of heat, for example, is to be that which is everywhere present where heat is found, which is nowhere where heat is lacking, and which is present in greater degree where there is more heat, and in lesser degree where there is less heat. 1 What Bacon presents accordingly as Induction is certainly no simple enumeration, hut an involved process of abstraction, which rests upon the meta physical assumptions of the scholastic Formalism1 (cf. § 27, 3); the presage of the new is still quite embedded in the old habits of thought
2. It is accordingly comprehensible that Bacon was not the marr to bring to the study of Nature itself methodical or material
furtherance : but this derogates nothing from his philosophical importance,3 which consists just in this, that he demanded the gen eral application of a principle, to which he yet was unable to give any useful or fruitful form in the case of the most immediate object for its use : namely, the knowledge of the corporeal world. He had understood that the new science must turn from the endless discussion of conceptions back to things themselves, that it can build only upon direct perception, and that it must rise from this only cautiously and gradually to the more abstract, * and he had understood no less clearly that in the case of this Induction, the point at issue was nothing other than the discovery of the simple
1 In which case it turns out that the Form of heat is motion, and, indeed, a motion which is expansive, and thus divided by inhibition and communicated to the smaller parts of the body [motut ezpanrivui, cohibitus et nitent per parte*
minora].
« Cf. Cbr. Sigwart, Logilc, II. 5 93, 8.
» Cf. Chr. Sigwart in the Preuts. Jahrb. , 1863, 93 ff.
• The pedagogiral consequences of the Baconian doctrine aa contrasted with Humanism, with which, in general, the movement of natural science came in conflict in tliis respect, were drawn principally by Amos Comeniui (1692-1871). Ilia Didafticn Magna presents the course of instruction an a graded ascent fr the concrete and perceptive to the more abstract ; his Orbit Pictus aims to (five for the Mchool a perceptional basis for instruction about things ; his Janva Lin- guarurn Jteterrata, finally, aims to have the learning of foreign languages arranged so as to be taught only as it is requisite as a means for acquiring knowledge about things.
The pedagogical views of Kattich are similar (1571- 1836).
386 The Renaissance : Natural Science Period. [Part I V.
elements of reality, from the " nature " of which, in their regular relation and connection, the whole compass of what we perceive is to be explained. Induction, he thought, will find the Forms by which Nature must be interpreted. But while in his cosmology he did not get far beyond an adherence to the traditional atomism, and even shut himself up against the great achievement of the Copernican theory, he demanded that his empirical principle should be applied also to knowledge of man. Not only the bodily existence in its normal and abnormal vital processes, but also the movement of ideas and of activities of the will, especially also the social and political system, — all these should be examined as to their mov ing forces ("Forms") by the method of natural science, and ex plained without prejudice. The anthropological and social naturalism which Bacon announces in the encyclopaedic remarks of his work De Augmentis Scientiarum, contains examples of programmes ' for many branches of knowledge, and proceeds everywhere from the fundamental purpose to understand man and all the activities of his life as a product of the same simple elements of reality which also lie at the basis of external Nature.
Still another element comes to light in this anthropological inter est. To understand man is not, for Bacon, an end in itself, any more than it is such to understand Nature. His entire thought is rather subordinated to a practical end, and this he conceives in the grandest form. All human knowledge has ultimately for its sole task to procure for man dominion over the world by his knowledge of the world. Knowledge is power, and is the only lasting power. While therefore magic with fantastic arts sought to make itself master of the working forces of Nature, this blind endeavour became clarified with Bacon to the insight that man can owe his mastery over things only to a sober investigation of their true essence. For him, therefore, the interpretatio natural is only the means of subjecting nature to the human mind, and his great work for the " Renovation of the Sciences "— Instauratio Magna, " Temporis Par tus Maximus " — bears also the title De Regno Hominis.
In this, Bacon expressed what was moving the heart of thousands at his time, under the impress of great events. With that series of discoveries beyond the seas, where through mistakes, adventures, and crimes, man had at last for the first time taken complete pos session of his planet, with inventions such as those of the mariner's compass, of gunpowder, and of the art of printing,* a mighty
1 If we could therefore regard as accomplished all that Bacon sets before him in prospect, we might find with him the entire natural science of to-day.
a Cf. O. Peschel, Oesch. des Zeitalters der Entdeckunyen, 2d ed. , Leips. 1879.
Chap. 2, § 30. ] Problem of Method : Bacon. 387
change had been introduced within a short time into the greater as well as the lesser life of man. A new epoch of civilisation seemed to be opened, and an exotic excitement seized upon men's fancy. Unheard-of things should succeed; nothing was to be impossible any longer. The telescope disclosed the mysteries of the heavens, and the powers of the earth began to obey the investigator. Science would be the guide of the human mind in its victorious journey through Nature. By her inventions, human life should be completely transformed. What hopes in this respect set free the fancy for its flights we see from Bacon's Utopian fragment of the Xova Atlantis, and also from Campanella's Civitas Solis. The English Chancellor, however, held that the task of the knowledge of Nature was ultimately to make of invention, which had hitherto been for the most part a matter of chance, a consciously exercised art. To be sure, he gave life to this thought only in the fantastic picture of Solomon's house, in his Utopia ; he guarded himself from seriously carrying it out ; but this meaning which he attributed to the ars inveniendi made him an opponent of purely theoretical and " contemplative " knowledge ; just from this point of view did he combat Aristotle and the unfruitfulness of monastic science. In his hand philosophy was in danger of falling from the rule of a religious end under that of technical interests.
But the issue proved again that the golden fruits of knowledge ripen only where they are not sought. In his haste for utility Bacon missed his goal, and the intellectual creations which have enabled natural science to become the basis of our external civilisa tion proceeded from the superior thinkers, who, with pure disinter ested thought, and without any eagerness to improve the world, desired to understand the order of Nature which they admired.
8. His tendency toward the practical end of invention blinded Bacon to the theoretical value of mathematics. This value had at first come to consciousness in the fantastic forms which praised the numlier-harmony of the universe in Neo-Platonio exuberance
(cf. f 29, 5), imitating the Pythagorean methods. The great investiga
tors of Nature set out from a like admiration for the beauty and order of the universe ; but the new in their teachings consists in just this, that they no longer seek this mathematical significance of the cosmical order in symbolic numlHT-speoulations, but aim to understand and prove it from fact*. Modern investigation of Nature was born as empirical Pythagoreanism. This problem had been seen already by Leonardo da Vinci1 — to have been the first to solve it
1 Cf. with regard to bim as a philosopher, K. l'rantl, Sitz. -Ber. der Jftin- rk'ntr Mad. . 1886, 1 fl.
388 The Renaissance : Natural Science Period. [Part IV.
is the glory of Kepler. The psychological motive of his research was the philosophical conviction of the mathematical order of the universe, and he verified his conviction by discovering the laws of planetary motion by means of a grand induction.
In this procedure it became evident, on the one hand, that the true task of induction in natural science consists in finding out that mathematical relation which remains the same in the entire series of the phenomena determined by measurement, and, on the other
hand, that the object, in connection with which this task can be performed by research, is none other than motion. The divine arithmetic and geometry which Kepler sought in the universe was found in the laws of occurrence and change {Oeschehens). Proceed ing from this principle, with a more distinct methodical conscious ness, Galileo created mechanics as the mathematical theory of motion. It is extremely instructive to compare the thoughts which the latter presents in the Saggiatore with Bacon's interpretation of Nature. Both aim to analyse into their elements the phenomena given in per ception, in order to explain phenomena from the combination of these elements. But where Bacon's Induction seeks the " Forms, " Galileo's method of resolution (analysis) searches out the simplest processes of motion capable of mathematical determination ; and while interpretation with the former consists in pointing out how the natures co-operate to form an empirical structure, the latter shows in his method of composition (synthesis) that the mathemati cal theory under the presupposition of the simple elements of motion leads to the same results which experience exhibits. 1 From this standpoint experiment also acquires quite another significance : it is not merely a shrewd question put to Nature, but is the intelli gent and intentional interference^ by which simple forms of occur rence are isolated in order to subject them to measurement. Thus, all that Bacon had merely presaged receives with Galileo a definite significance usable for the investigation of Nature, by means of the mathematical principle and its application to motion ; and in accord ance with these principles of mechanics Newton was able by his hypothesis of gravitation to give the mathematical theory for the explanation of Kepler's laws.
With this, the victory of the principle of Democritus and Plato, that the sole object which true knowledge of Nature can deal with is what is capable of quantitative determination, was sealed in a completely new form ; but this time the principle was applied not to the Being, but to the Becoming or change in Nature. Scientific
1 This methodical standpoint Hoboes makes entirely hiB own (cf. Dr Corp. , ch. 6), and indeed in expressly rationalistic antithesis to the empiricism of Bacon.
Chak 2, $ 30. ] Problem of Method : Galileo, Holies. 389
insight reaches as far as the mathematical theory of motion extends. Exactly this standpoint of the Galilean physics is taken in theoreti cal philosophy by Ilobbes. 1 Geometry is the only certain discipline ; all knowledge of Nature is rooted in it. We can know only such objects as we can construct, so that we derive all further conse quences from this our own operation. Hence knowledge of all things, in so far as it is accessible for us, consists in tracing back what is perceived to motion of bodies in space. Science has to reason from phenomena to causes, and from these latter in turn to their effects : but phenomena are, in their essence, motions ; causes are the simple elements of motion, and effects are again motions. Thus arises the apparently materialistic proposition : philosophy is the doctrine of the motion of bodies ! This is the extreme conse quence of the separation of philosophy from theology, which begun with the English Franciscans.
The essential result for philosophy in these methodical begin nings of natural research therefore, twofold: empiricism was corrected by mathematics, and the shapeless Pythagoreanism of the humanistic tradition was made by empiricism definite mathemati cal theory. These lines meet and are bound together in Galileo.
4. In mathematical theory, accordingly, was found that rational factor which Giordano Bruno had demanded in his treatment of the Copernican doctrine for a critical elaboration of sense perception. ' Rational science mathematics. Proceeding from this conviction, Detcarttt undertook his reform of philosophy. Educated in the Scholasticism of the Jesuits, he had attained the personal convic tion that satisfaction for an earnest craving for truth was to be found neither in metaphysical theories nor in the learned polymathy of the empirical disciplines, but in mathematics alone and by follow ing the pattern of mathematics, — himself, as well known, a cre ative mathematician, — he thought to transform all the rest of human knowledge his philosophy aims to be universal mathematics. In the generalisation of the Galilean principle requisite for this pur pose, some of the factors which made the principle fruitful for the
special tasks of natural research fell away, so that Descartes' teach ing not usually counted as an advance in the history of physics; but the power of his influence upon the philosophical development, in which he was the ruling mind for the seventeenth century and beyond, was all the greater.
To those methodical thoughts which are common to Bacon and
Cf. the beginning of Dt Corport.
O. Bruno, Deir Inf. fair, Mond in. (L. 307 f. ). Cf. the tine exposition in the JUtcuun de la Mttkode.
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390 The Renaissance : Natural Science Period. [Pabt IV.
Galileo, Descartes added a postulate of the greatest importance : he demanded that the method of induction or resolution should lead to a single principle of highest and absolute certainty, from which after wards, by the method of composition, the whole compass of experi ence must find its explanation. This demand was entirely original, and had its root in the felt need for a systematic, connected whole of all human knowledge ; it rested ultimately upon his surfeit of the traditional reception of historically collected knowledge, and upon his longing for a new philosophical creation from one mould. Descartes will, then, by an inductive enumeration and a critical sifting of all ideas, press forward to a single, certain point, in order from this point to deduce all further truths. The first task of phil osophy is analytic, the second synthetic.
The classical carrying out of this thought is presented in the Meditations. The philosopher portrays his struggle after truth in a dramatic dialogue with himself. Proceeding from the principle " de omnibus dubitandum," the whole circuit of ideas is reviewed on all sides, and in the process we meet the whole apparatus of sceptical arguments. We experience the change of opinions and the deceptions of the senses too often, says Descartes, to permit of our trusting them. In the face of the variety of impressions which the same object makes under different circumstances, it is not possible to decide which of these impressions, and, indeed, whether any one of them, contains the true essence of the thing ; and the liveliness and sureness with which we can dream in our actual experience must excite in us the scruple which can never be completely set aside, as to whether we are not perhaps dreaming even when we believe that we are awake and perceiving. Meanwhile, at the basis of all the combinations which the imagination can produce lie the simple elementary acts of consciousness, and in connection with these we meet with truths of which we are undeniably obliged to say that we cannot help recognising them, as, for example, the simple propositions of arithmetic 2x2 = 4, and the like. But how if now we were so constituted that from our very nature we must necessarily err ? how if some demon had created us, whose pleasure it was to give us a Eeason that would necessarily deceive while it supposed itself to be teaching the truth ? Against such a
delusion we should be defenceless, and this thought must make us mistrustful even with reference to the most evident utterances of reason.
After fundamental doubt has been thus pressed even to the far thest extreme, it proves that the doubt breaks off its own point, that it itself presents a fact of completely unassailable certainty :
Chap. 2, § 30. ] Problem of Method : Descartes. 391
in order to doubt, in order to dream, in order to be deceived, I must
be. Doubt itself proves that I, as a thinking conscious
cogitans), exist. The proposition cogito sum is true as often as I think or pronounce it. And, indeed, the certainty of Being is con tained in none of my activities except that of consciousness. That 1 go to walk I can imagine in my dream : ' that I am conscious can not be merely my imagination, for imagination is itself a kind of consciousness. 1 The certainty of the Being or existence of conscious
ness is the one fundamental truth which Descartes finds by the analytic method.
Rescue from doubt consists therefore in the Augustinian argument of the Reality of the conscious nature or essence (cf. § 22, 1). But its application with Descartes3 is not the same as with Augustine himself and with the great number of those on whom his doctrine was influential just in the transition period. For Augustine, the self-certainty of the soul was valued as the surest of all experiences, as the fundamental fact of inner perception by means of which the latter obtains for the theory of knowledge a preponderance over outer perception. Thus — not to recall again Charron's moralising
interpretation — Campanella particularly had employed the Augus tinian principle when, not unlike the great Church Father, he gave to the elements of this experience of self the meaning of metaphysi cal prime elements (cf. § 29, 3). In a completely analogous manner — not to speak of Locke 4 — Tschirnhausen, in a supposed adherence to Descartes, had later regarded self-knowledge as the experientia evi- dentissima,* which is therefore to serve as the a posteriori beginning of philosophy (cf. below, No. 7), so that from it all further knowledge can be constructed a priori ; for in self-knowledge is contained the threefold truth, that we are effected by some things well and by others ill, that we understand some and not others, and that in the process of ideation we occupy a passive attitude with reference to
•The ordinary translation of togitare, tngitatio by "think" (Denken) in liable to occasion misunderstanding, Hinoe Di'nktn in Herman [and the same is true of Mini-, in English, at least in philosophical terminology] signifies a par ticular kind of theoretical consciousness. Descartes himself elucidates the mean
ing of togitare (Med. III.
; Print. Phil. I. 9), by enumeration : he understands by it to doubt, affirm, deny, understand, will, abhor, imagine, feel a sensation, etc. For that which Is common to all these functions we have in (ierman scarcely any word but " Bewusstsein" [consciousness]. The same is also true with regard to Spinoza's use of the term ; cf. his IYint. Phil. Cart. I. , Prop. IV. ,
this argument. Cf. Ob). IV. , and Retp.
* Cf. below, §§ 33 f.
* Tachimhausen, MeJ. Ment. 0895), pp. 290-94.
Schol. . and also Eth. II. , Ax. III. , and elsewhere.
* Who besides, at the outset, seems not to have known the historical origin of
being (res
' Descartes' reply to Oasaendi's objection (V. 2) ; cf. Print. Phil. I. 9.
392 The Renaissance : Natural Science Period. [Part IV.
the outer world, — three points of attachment for the three rational sciences, ethics, logic, and physics.
5. With Descartes, on the contrary, the proposition cogilo sum has not so much the meaning of an experience, as rather that of the first fundamental rational truth. Nor is its evidence that of an infer ence,1 but that of immediate intuitive certainty. The analytic method seeks here, as with Galileo, the simple, self-intelligible elements, out of which all else is to be explained ; but while the physicist discovers the perceptional elementary form of motion, which is to make com prehensible all that takes place in the corporeal world, the meta physician is hunting for the elementary truths of consciousness. In this consists the rationalism of Descartes.
This rationalism expresses itself in the fact that the superiority of self-consciousness is found in its complete clearness and distinct ness, and in the fact that Descartes propounded as his principle for the synthetic method the maxim, Everything must be true which is as clear and distinct as self-consciousness, i. e. which presents itself before the mind's vision as surely and underivably as the mind's own exist ence. " Clear " is defined by Descartes * as that which is intuitively present and manifest to the mind, " distinct " as that which is en tirely clear in itself and precisely determined. And those mental presentations — or ideas," as he calls them after the manner of later Scholasticism — which are in this sense clear and distinct, whose evidence is not to be deduced from any others, but is grounded solely in themselves, he calls innate ideas. * With this expression he indeed incidentally connects also the psycho-genetic thought that these ideas are imprinted upon the human soul by God, but for the most part he desires to give only the epistemological significance of immediate, rational evidence.
These two meanings are peculiarly mingled in Descartes' proofs for the existence of God, which form an integrant constituent of his theory of knowledge, in so far as this "idea" is the first for which,
in the synthetic procedure of his method a clearness and distinct ness or intuitive evidence of the " natural light," equal to that of self-consciousness, is claimed. The new (so-called Cartesian) proof which he introduces in this connection," has a multitude of scholastic
> Resp. ad Obj. II. i Princ. Phil. I. 45.
8 [German Idee. I follow the ordinary English usage in spelling the word as used by Descartes without a capital. ]
4 Cf. E. Grimm, D. 's Lehre ron den angeborenen Ideen (Jena, 1873), and also P. Natorp, Z>. '« Erkenntnisstheorie (Marburg, 1882). That in nut us is better translated by eingeboren than by the usual angeboren has been remarked by R. Eucken, Qeachichte und Kritik der Grundbegriffe der Oegenwart, p. 73.
* Med.
Of philosophical writers in Germany who attached themselves to the train of the movement among the two civilised peoples of the West are to be mentioned Joachim Jung (1587-1667 Logica Hamburgiensis, 1638); cf. G. E. Guhrauer.
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382 The Renaissance : Natural Science Period. [Part IV.
J. J. und sein Zeitalter (Stuttg. and Tfib. 1859); the Jena mathematician, Erhard VVeigel, the teacher of Leibniz and Puffendorf ; Walther von Tschirn- hausen (1661-1708 ; Medicina Mentis sive Artis Inveniendi Prcecepta Generalia, Amsterdam, 1087), and Samuel Puffendorf (1032-1694; under the pseudonym Severinus a Monzambano, De Statu Bei publico: Germanicce, 1667, German by H. Bresslau, Berlin, 1870 ; De Jure Naturae et Gentium, London, 1672).
Leibniz belongs in this period, not only in point of time, but also as regards the origination and the motives of his metaphysics, while with other interests of his incredibly many-sided nature, he ranges on into the age of the Enlighten ment ; cf. on this, Part V. Here, therefore, we have to consider principally his methodological and metaphysical writings : De Principio Individui, 1663 ; De Arte Combinatoria, 1666 ; Nova Methodus pro Maximis et Minimis, 1684 ; De Scientia Universali seu Calculo Philosophico, 1684 (cf. A. Trendelenburg, Hist. Beitrage zur Philos. , III. 1 ff. ); De Prima: Philosophies Emendatione, 1694; Systeme Nouveau de la Nature, 1695, with the three Eclaircissements connected with it, 1696 ; also the Monadologie, 1714, the Principes de la Nature et de la Grace, 1714, and a great part of his extended correspondence. Among the editions of his philosophical writings the excellent edition by J. E. Erdmann (^Berlin, 1840) has now been surpassed by that of C. J. Gerhardt (7 vols. , Ber lin, 1875-91). — On the system as a whole cf. L. Feuerbach, Darstellung, Ent- vricklnng und Kritik der Leibnizischen Philos. (Ansbach, 1837), A. Nourisson, La Philos. de L. (Paris, 1860); E. Wendt, Die Entwicklung der LSschen Mo- nadenlehre bis 1695 (Berlin, 1886). [E. Dillmann, Sine neue Darst. der L. 'schen Monadenlehre, Leips. 1891. See also the lit. on p. 444. ]
On the historical and systematic relation of the systems to one another : H. C. W. Sigwart, Ueber den Zusammenhang des Spinozismus mit der cartes. Philos. (Tub. 1816) and Die Leibniz'sche Lehre von der prastabilirten Harmonie in ihrem Zusammenhang mit fruheren Philosophemen (ib. 1822) ; C. Schaar- schmidt, Descartes und Spinoza (Bonn, 1860) ; A. Foucher de Careil, Leibniz, Descartes et Spinoza (Paris, 1863) ; E. Pfleiderer, L. und Geulincx (Tub. 1884); E. Zeller, Sitz. -Ber. d. Berliner Akad, 1884, pp. 673 ff. ; F. Tonnies, Leibniz und Hobbes in Philos. Monatsh; 1887, pp. 357 ft*. ; L. Stein, Leibniz und Spinoza (Berlin, 1890). [E. Caird, Art Cartesianism, in Enc. Brit. , reprinted in Vol. 2 of his Essays, Lond. and N. Y. 1892 ; Saisset's Modern Pantheism. ]
To the founders of the philosophy of law (cf. C. v. Kaltenborn, Die Vorlaufer des Hugo Grotius, Leips. 1848 ; and B. v. Mohl, Gesch. und Litteratur der Staatswissenschaften, Erlangen, 1866-68) belong Nicolo Macchiavelli (1469- 1627 ; H Principe, Discorsi sulla prima decade di Tito Livio ; [Works, tr. by C. E. Detmold, Boston, 1883. ] Thomas More (1480-1636 ; De Optimo Bei publico- Statu sive de Nova Insula Utopia, 1516) ; Jean Bodin (1530-1697) ; Six Livres de la Bipublique, 1577; an extract from the Heptaplomeres has been given by Guhrauer, Berlin, 1841) ; Albericus Oentilis (1551-1611 ; De Jure Belli, 1688) ; Johannes Althus (1557-1638 ; Politico, Groningen, 1610, cf. O. Gierke, Unters. z. deutsch. Staats- u. Bechtsgesch. , Breslau, 1880); Hugo de Groot (1583-1645 ; De Jure Belli et Pacis, 1646; cf. H. Luden, H. G. , Berlin, 1806).
Of the Protestants who treat of the philosophy of law may be named, be sides Melancthon, J. Oldendorf (Elementaris Introductio, 1539), Nic. Hemming
(De Lege Natural, 1562), Ben Winkler (Principia Juris, 1615) ; of the Catho lics besides Suarez, Rob. Bellarmin (1642-1621 ; De Potentate Pontijicis in
Temporalibus) and Mariana (1537-1624 ; De Bege et Begis Institutione).
Natural religion and natural morals in the seventeenth century found in England their main supporters in Herbert of Cnerbury (1581-1648 ; Tractatus de Veritate, 1624 ; De Beligione Gentilium Errorumque apud eos Causis, 1663 ; on him Ch. de Remusat, Paris, 1873), and Richard Cumberland (De Legibu* Natural Disquisitio Philosophica, Lond. 1672). Among the Platonists or Neo-
Platonists of England at the same time are prominent Ralph Cudworth (1617— 1688 ; The Intellectual System of the Universe, Lond. 1678, Latin, Jena, 1783) and Henry More (1614-1687 ; Encheiridion Metaphysicum. His correspondence with Descartes is printed in the latter's works, Vol. X. , Cousin's ed. ). [Pfcrt. of Cudworth, by C. E. Lowrey, with bibliog. , N. Y. 1884; Tulloch's Rational Theol. and Christian Phil, in Eng. in ^^th Cent. ] Theophilus Gale and his son, Thomas Gale, may be added to the authors above.
Chap. 2, $ 30. ] Problem of Method : Bacon. 383
§ 30. The Problem of Method.
All beginnings of modern philosophy have in common an impul sive opposition against "Scholasticism," and at the same time a naive lack of understanding for the common attitude of dependence upon some one of its traditions, which they nevertheless all occupy. This fundamental oppositional character brings with it the conse quence, that in all cases where it is not merely wants of the feelings, or fanciful views that are set over against the old doctrines, reflec tion on new methods of knowledge stands in the foreground. Out of the insight into the unfruitfulness of the " syllogism," which could merely set forth in proof or refutation that which was already known, or apply the same to a particular case, arises the demand for an ars inveniendi, a method of investigation, a sure way to the discovery of the new.
1. If now nothing was to be accomplished with the help of rhetoric, the nearest expedient was to attack the matter by the reverse method, proceeding from the particular, from the facts. This had been commended by Vives and Sanchez, and practised by Telesio and Campanella. But they had neither gained full confi dence in experience nor known afterwards how to make any right beginning with their facts. In both lines Bacon believed that he could point out new paths for science, and in this spirit he set up his " New Organon " as over against the Aristotelian.
Every -day perception — he confesses, admitting the well-known sceptical arguments — offers, indeed, no sure basis for a true knowl edge of Nature ; in order to become an experience that can be used by science it must first be purified from all the erroneous additions which have grown together with it in our involuntary way of regard ing things. These perversions or falsifications of pure experience Bacon calls idols, and presents his doctrine of these fallacious images in analog}' with the doctrine of the fallacious conclusions in the old dialectic. 1 There are first the "idols of the tribe" (idola tribus), the illusions that are given in connection with human nature in general, following which we are always suspecting an order and an end in things, making ourselves the measure of the outer world, blindly retaining a mode of thought which has once been excited by impressions, and the like; then the "idols of the cave" (idola specus), by reason of which every individual by his natural disposi tion, and his situation in life, finds himself shut into his cave;*
• Nov. Org. I. 39 fl.
* Bacon'* utrotigly rhetorical language, rich in imagery, aims by this term let Dt Auf/m. V. ch. 4) to recall Plato'* well-known parable of the Cave (Xtp-
384 The Renaissance : Natural Science Period. [Part IA .
then the "idols of the market" (idola fori), the errors which axe everywhere brought about by intercourse among men, especially by language, and by adherence to the word which we substitute for the idea; finally, the "idols of the theatre" (idola theatri), the illusory
of theories which we credulously receive from human history and repeat without subjecting them to any judgment of our own. In this connection Bacon finds opportunity to direct a most violent polemic against the word-wisdom of Scholasticism, against the rule of authority, against the anthropomorphism of earlier philosophy, and to demand a personal examination of things them selves, an unprejudiced reception of reality. Nevertheless he does not get beyond this demand ; for the statements as to how the mera experientia is to be gained and separated from the enveloping husks of the idols are extremely meagre, and while Bacon teaches that one must not limit himself to accidental perceptions, but must set about his observation methodically, and supplement ix bv experiment ' which he thinks out and makes for himself, this also is but a general designation of the task, and a theoretical insight into the essential nature of experiment is still wanting.
Quite similar is the case with the method of Induction, which Bacon proclaimed as the only correct mode of elaborating facts. With its aid we are to proceed to general cognitions (axioms), in order that we may ultimately from these explain other phenomena. In this activity the human mind, among whose constitutional errors is over-hasty generalisation, is to be restrained as much as possible; it is to ascend quite gradually the scale of the more general, up to the most general. Healthy and valuable as these prescriptions are, we are the more surprised to find that with Bacon their more de tailed carrying out is completed in conceptions and modes of view which are entirely scholastic*
All knowledge of Nature has for its end to understand the causes of things. Causes, however, are — according to the old Aristotelian scheme — formal, material, efficient, or final. Of these only the " formal " causes come into consideration ; for all that takes place has its grounds in the " Forms," in the " natures " of things. Hence when Bacon's Induction searches for the "Form" of phenomena, e. g. for the Form of heat, Form is here understood quite in the sense of Scotism as the abiding essence or nature of phenomena. The Form of that which is given in perception is composed out of
phantoms
614), which is the more unfortunate as, in the Platonic passage, it is precisely the general limited nature of knowledge by the senses that is dealt with.
> Nov. Org. I. 82.
1 Cf. the circumstantial exposition in the second book of the Nov. Org
Chap. 2, § 30. ] Problem of Method : Bacon. 385
simpler " Forms " and their " differences," and these it is important to discover. To this end as many cases as possible in which the phenomenon in question appears, are brought together into a tabula prvesentios, and in like manner, those in which the phenomenon is lacking are brought together into a tabula absentia;; to these is added, in the third place, a tabula graduum, in which the varying intensity with which the phenomenon appears is compared with the varying intensity of other phenomena. The problem is then to be solved by a progressive process of exclusion (exclusio). The Form of heat, for example, is to be that which is everywhere present where heat is found, which is nowhere where heat is lacking, and which is present in greater degree where there is more heat, and in lesser degree where there is less heat. 1 What Bacon presents accordingly as Induction is certainly no simple enumeration, hut an involved process of abstraction, which rests upon the meta physical assumptions of the scholastic Formalism1 (cf. § 27, 3); the presage of the new is still quite embedded in the old habits of thought
2. It is accordingly comprehensible that Bacon was not the marr to bring to the study of Nature itself methodical or material
furtherance : but this derogates nothing from his philosophical importance,3 which consists just in this, that he demanded the gen eral application of a principle, to which he yet was unable to give any useful or fruitful form in the case of the most immediate object for its use : namely, the knowledge of the corporeal world. He had understood that the new science must turn from the endless discussion of conceptions back to things themselves, that it can build only upon direct perception, and that it must rise from this only cautiously and gradually to the more abstract, * and he had understood no less clearly that in the case of this Induction, the point at issue was nothing other than the discovery of the simple
1 In which case it turns out that the Form of heat is motion, and, indeed, a motion which is expansive, and thus divided by inhibition and communicated to the smaller parts of the body [motut ezpanrivui, cohibitus et nitent per parte*
minora].
« Cf. Cbr. Sigwart, Logilc, II. 5 93, 8.
» Cf. Chr. Sigwart in the Preuts. Jahrb. , 1863, 93 ff.
• The pedagogiral consequences of the Baconian doctrine aa contrasted with Humanism, with which, in general, the movement of natural science came in conflict in tliis respect, were drawn principally by Amos Comeniui (1692-1871). Ilia Didafticn Magna presents the course of instruction an a graded ascent fr the concrete and perceptive to the more abstract ; his Orbit Pictus aims to (five for the Mchool a perceptional basis for instruction about things ; his Janva Lin- guarurn Jteterrata, finally, aims to have the learning of foreign languages arranged so as to be taught only as it is requisite as a means for acquiring knowledge about things.
The pedagogical views of Kattich are similar (1571- 1836).
386 The Renaissance : Natural Science Period. [Part I V.
elements of reality, from the " nature " of which, in their regular relation and connection, the whole compass of what we perceive is to be explained. Induction, he thought, will find the Forms by which Nature must be interpreted. But while in his cosmology he did not get far beyond an adherence to the traditional atomism, and even shut himself up against the great achievement of the Copernican theory, he demanded that his empirical principle should be applied also to knowledge of man. Not only the bodily existence in its normal and abnormal vital processes, but also the movement of ideas and of activities of the will, especially also the social and political system, — all these should be examined as to their mov ing forces ("Forms") by the method of natural science, and ex plained without prejudice. The anthropological and social naturalism which Bacon announces in the encyclopaedic remarks of his work De Augmentis Scientiarum, contains examples of programmes ' for many branches of knowledge, and proceeds everywhere from the fundamental purpose to understand man and all the activities of his life as a product of the same simple elements of reality which also lie at the basis of external Nature.
Still another element comes to light in this anthropological inter est. To understand man is not, for Bacon, an end in itself, any more than it is such to understand Nature. His entire thought is rather subordinated to a practical end, and this he conceives in the grandest form. All human knowledge has ultimately for its sole task to procure for man dominion over the world by his knowledge of the world. Knowledge is power, and is the only lasting power. While therefore magic with fantastic arts sought to make itself master of the working forces of Nature, this blind endeavour became clarified with Bacon to the insight that man can owe his mastery over things only to a sober investigation of their true essence. For him, therefore, the interpretatio natural is only the means of subjecting nature to the human mind, and his great work for the " Renovation of the Sciences "— Instauratio Magna, " Temporis Par tus Maximus " — bears also the title De Regno Hominis.
In this, Bacon expressed what was moving the heart of thousands at his time, under the impress of great events. With that series of discoveries beyond the seas, where through mistakes, adventures, and crimes, man had at last for the first time taken complete pos session of his planet, with inventions such as those of the mariner's compass, of gunpowder, and of the art of printing,* a mighty
1 If we could therefore regard as accomplished all that Bacon sets before him in prospect, we might find with him the entire natural science of to-day.
a Cf. O. Peschel, Oesch. des Zeitalters der Entdeckunyen, 2d ed. , Leips. 1879.
Chap. 2, § 30. ] Problem of Method : Bacon. 387
change had been introduced within a short time into the greater as well as the lesser life of man. A new epoch of civilisation seemed to be opened, and an exotic excitement seized upon men's fancy. Unheard-of things should succeed; nothing was to be impossible any longer. The telescope disclosed the mysteries of the heavens, and the powers of the earth began to obey the investigator. Science would be the guide of the human mind in its victorious journey through Nature. By her inventions, human life should be completely transformed. What hopes in this respect set free the fancy for its flights we see from Bacon's Utopian fragment of the Xova Atlantis, and also from Campanella's Civitas Solis. The English Chancellor, however, held that the task of the knowledge of Nature was ultimately to make of invention, which had hitherto been for the most part a matter of chance, a consciously exercised art. To be sure, he gave life to this thought only in the fantastic picture of Solomon's house, in his Utopia ; he guarded himself from seriously carrying it out ; but this meaning which he attributed to the ars inveniendi made him an opponent of purely theoretical and " contemplative " knowledge ; just from this point of view did he combat Aristotle and the unfruitfulness of monastic science. In his hand philosophy was in danger of falling from the rule of a religious end under that of technical interests.
But the issue proved again that the golden fruits of knowledge ripen only where they are not sought. In his haste for utility Bacon missed his goal, and the intellectual creations which have enabled natural science to become the basis of our external civilisa tion proceeded from the superior thinkers, who, with pure disinter ested thought, and without any eagerness to improve the world, desired to understand the order of Nature which they admired.
8. His tendency toward the practical end of invention blinded Bacon to the theoretical value of mathematics. This value had at first come to consciousness in the fantastic forms which praised the numlier-harmony of the universe in Neo-Platonio exuberance
(cf. f 29, 5), imitating the Pythagorean methods. The great investiga
tors of Nature set out from a like admiration for the beauty and order of the universe ; but the new in their teachings consists in just this, that they no longer seek this mathematical significance of the cosmical order in symbolic numlHT-speoulations, but aim to understand and prove it from fact*. Modern investigation of Nature was born as empirical Pythagoreanism. This problem had been seen already by Leonardo da Vinci1 — to have been the first to solve it
1 Cf. with regard to bim as a philosopher, K. l'rantl, Sitz. -Ber. der Jftin- rk'ntr Mad. . 1886, 1 fl.
388 The Renaissance : Natural Science Period. [Part IV.
is the glory of Kepler. The psychological motive of his research was the philosophical conviction of the mathematical order of the universe, and he verified his conviction by discovering the laws of planetary motion by means of a grand induction.
In this procedure it became evident, on the one hand, that the true task of induction in natural science consists in finding out that mathematical relation which remains the same in the entire series of the phenomena determined by measurement, and, on the other
hand, that the object, in connection with which this task can be performed by research, is none other than motion. The divine arithmetic and geometry which Kepler sought in the universe was found in the laws of occurrence and change {Oeschehens). Proceed ing from this principle, with a more distinct methodical conscious ness, Galileo created mechanics as the mathematical theory of motion. It is extremely instructive to compare the thoughts which the latter presents in the Saggiatore with Bacon's interpretation of Nature. Both aim to analyse into their elements the phenomena given in per ception, in order to explain phenomena from the combination of these elements. But where Bacon's Induction seeks the " Forms, " Galileo's method of resolution (analysis) searches out the simplest processes of motion capable of mathematical determination ; and while interpretation with the former consists in pointing out how the natures co-operate to form an empirical structure, the latter shows in his method of composition (synthesis) that the mathemati cal theory under the presupposition of the simple elements of motion leads to the same results which experience exhibits. 1 From this standpoint experiment also acquires quite another significance : it is not merely a shrewd question put to Nature, but is the intelli gent and intentional interference^ by which simple forms of occur rence are isolated in order to subject them to measurement. Thus, all that Bacon had merely presaged receives with Galileo a definite significance usable for the investigation of Nature, by means of the mathematical principle and its application to motion ; and in accord ance with these principles of mechanics Newton was able by his hypothesis of gravitation to give the mathematical theory for the explanation of Kepler's laws.
With this, the victory of the principle of Democritus and Plato, that the sole object which true knowledge of Nature can deal with is what is capable of quantitative determination, was sealed in a completely new form ; but this time the principle was applied not to the Being, but to the Becoming or change in Nature. Scientific
1 This methodical standpoint Hoboes makes entirely hiB own (cf. Dr Corp. , ch. 6), and indeed in expressly rationalistic antithesis to the empiricism of Bacon.
Chak 2, $ 30. ] Problem of Method : Galileo, Holies. 389
insight reaches as far as the mathematical theory of motion extends. Exactly this standpoint of the Galilean physics is taken in theoreti cal philosophy by Ilobbes. 1 Geometry is the only certain discipline ; all knowledge of Nature is rooted in it. We can know only such objects as we can construct, so that we derive all further conse quences from this our own operation. Hence knowledge of all things, in so far as it is accessible for us, consists in tracing back what is perceived to motion of bodies in space. Science has to reason from phenomena to causes, and from these latter in turn to their effects : but phenomena are, in their essence, motions ; causes are the simple elements of motion, and effects are again motions. Thus arises the apparently materialistic proposition : philosophy is the doctrine of the motion of bodies ! This is the extreme conse quence of the separation of philosophy from theology, which begun with the English Franciscans.
The essential result for philosophy in these methodical begin nings of natural research therefore, twofold: empiricism was corrected by mathematics, and the shapeless Pythagoreanism of the humanistic tradition was made by empiricism definite mathemati cal theory. These lines meet and are bound together in Galileo.
4. In mathematical theory, accordingly, was found that rational factor which Giordano Bruno had demanded in his treatment of the Copernican doctrine for a critical elaboration of sense perception. ' Rational science mathematics. Proceeding from this conviction, Detcarttt undertook his reform of philosophy. Educated in the Scholasticism of the Jesuits, he had attained the personal convic tion that satisfaction for an earnest craving for truth was to be found neither in metaphysical theories nor in the learned polymathy of the empirical disciplines, but in mathematics alone and by follow ing the pattern of mathematics, — himself, as well known, a cre ative mathematician, — he thought to transform all the rest of human knowledge his philosophy aims to be universal mathematics. In the generalisation of the Galilean principle requisite for this pur pose, some of the factors which made the principle fruitful for the
special tasks of natural research fell away, so that Descartes' teach ing not usually counted as an advance in the history of physics; but the power of his influence upon the philosophical development, in which he was the ruling mind for the seventeenth century and beyond, was all the greater.
To those methodical thoughts which are common to Bacon and
Cf. the beginning of Dt Corport.
O. Bruno, Deir Inf. fair, Mond in. (L. 307 f. ). Cf. the tine exposition in the JUtcuun de la Mttkode.
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390 The Renaissance : Natural Science Period. [Pabt IV.
Galileo, Descartes added a postulate of the greatest importance : he demanded that the method of induction or resolution should lead to a single principle of highest and absolute certainty, from which after wards, by the method of composition, the whole compass of experi ence must find its explanation. This demand was entirely original, and had its root in the felt need for a systematic, connected whole of all human knowledge ; it rested ultimately upon his surfeit of the traditional reception of historically collected knowledge, and upon his longing for a new philosophical creation from one mould. Descartes will, then, by an inductive enumeration and a critical sifting of all ideas, press forward to a single, certain point, in order from this point to deduce all further truths. The first task of phil osophy is analytic, the second synthetic.
The classical carrying out of this thought is presented in the Meditations. The philosopher portrays his struggle after truth in a dramatic dialogue with himself. Proceeding from the principle " de omnibus dubitandum," the whole circuit of ideas is reviewed on all sides, and in the process we meet the whole apparatus of sceptical arguments. We experience the change of opinions and the deceptions of the senses too often, says Descartes, to permit of our trusting them. In the face of the variety of impressions which the same object makes under different circumstances, it is not possible to decide which of these impressions, and, indeed, whether any one of them, contains the true essence of the thing ; and the liveliness and sureness with which we can dream in our actual experience must excite in us the scruple which can never be completely set aside, as to whether we are not perhaps dreaming even when we believe that we are awake and perceiving. Meanwhile, at the basis of all the combinations which the imagination can produce lie the simple elementary acts of consciousness, and in connection with these we meet with truths of which we are undeniably obliged to say that we cannot help recognising them, as, for example, the simple propositions of arithmetic 2x2 = 4, and the like. But how if now we were so constituted that from our very nature we must necessarily err ? how if some demon had created us, whose pleasure it was to give us a Eeason that would necessarily deceive while it supposed itself to be teaching the truth ? Against such a
delusion we should be defenceless, and this thought must make us mistrustful even with reference to the most evident utterances of reason.
After fundamental doubt has been thus pressed even to the far thest extreme, it proves that the doubt breaks off its own point, that it itself presents a fact of completely unassailable certainty :
Chap. 2, § 30. ] Problem of Method : Descartes. 391
in order to doubt, in order to dream, in order to be deceived, I must
be. Doubt itself proves that I, as a thinking conscious
cogitans), exist. The proposition cogito sum is true as often as I think or pronounce it. And, indeed, the certainty of Being is con tained in none of my activities except that of consciousness. That 1 go to walk I can imagine in my dream : ' that I am conscious can not be merely my imagination, for imagination is itself a kind of consciousness. 1 The certainty of the Being or existence of conscious
ness is the one fundamental truth which Descartes finds by the analytic method.
Rescue from doubt consists therefore in the Augustinian argument of the Reality of the conscious nature or essence (cf. § 22, 1). But its application with Descartes3 is not the same as with Augustine himself and with the great number of those on whom his doctrine was influential just in the transition period. For Augustine, the self-certainty of the soul was valued as the surest of all experiences, as the fundamental fact of inner perception by means of which the latter obtains for the theory of knowledge a preponderance over outer perception. Thus — not to recall again Charron's moralising
interpretation — Campanella particularly had employed the Augus tinian principle when, not unlike the great Church Father, he gave to the elements of this experience of self the meaning of metaphysi cal prime elements (cf. § 29, 3). In a completely analogous manner — not to speak of Locke 4 — Tschirnhausen, in a supposed adherence to Descartes, had later regarded self-knowledge as the experientia evi- dentissima,* which is therefore to serve as the a posteriori beginning of philosophy (cf. below, No. 7), so that from it all further knowledge can be constructed a priori ; for in self-knowledge is contained the threefold truth, that we are effected by some things well and by others ill, that we understand some and not others, and that in the process of ideation we occupy a passive attitude with reference to
•The ordinary translation of togitare, tngitatio by "think" (Denken) in liable to occasion misunderstanding, Hinoe Di'nktn in Herman [and the same is true of Mini-, in English, at least in philosophical terminology] signifies a par ticular kind of theoretical consciousness. Descartes himself elucidates the mean
ing of togitare (Med. III.
; Print. Phil. I. 9), by enumeration : he understands by it to doubt, affirm, deny, understand, will, abhor, imagine, feel a sensation, etc. For that which Is common to all these functions we have in (ierman scarcely any word but " Bewusstsein" [consciousness]. The same is also true with regard to Spinoza's use of the term ; cf. his IYint. Phil. Cart. I. , Prop. IV. ,
this argument. Cf. Ob). IV. , and Retp.
* Cf. below, §§ 33 f.
* Tachimhausen, MeJ. Ment. 0895), pp. 290-94.
Schol. . and also Eth. II. , Ax. III. , and elsewhere.
* Who besides, at the outset, seems not to have known the historical origin of
being (res
' Descartes' reply to Oasaendi's objection (V. 2) ; cf. Print. Phil. I. 9.
392 The Renaissance : Natural Science Period. [Part IV.
the outer world, — three points of attachment for the three rational sciences, ethics, logic, and physics.
5. With Descartes, on the contrary, the proposition cogilo sum has not so much the meaning of an experience, as rather that of the first fundamental rational truth. Nor is its evidence that of an infer ence,1 but that of immediate intuitive certainty. The analytic method seeks here, as with Galileo, the simple, self-intelligible elements, out of which all else is to be explained ; but while the physicist discovers the perceptional elementary form of motion, which is to make com prehensible all that takes place in the corporeal world, the meta physician is hunting for the elementary truths of consciousness. In this consists the rationalism of Descartes.
This rationalism expresses itself in the fact that the superiority of self-consciousness is found in its complete clearness and distinct ness, and in the fact that Descartes propounded as his principle for the synthetic method the maxim, Everything must be true which is as clear and distinct as self-consciousness, i. e. which presents itself before the mind's vision as surely and underivably as the mind's own exist ence. " Clear " is defined by Descartes * as that which is intuitively present and manifest to the mind, " distinct " as that which is en tirely clear in itself and precisely determined. And those mental presentations — or ideas," as he calls them after the manner of later Scholasticism — which are in this sense clear and distinct, whose evidence is not to be deduced from any others, but is grounded solely in themselves, he calls innate ideas. * With this expression he indeed incidentally connects also the psycho-genetic thought that these ideas are imprinted upon the human soul by God, but for the most part he desires to give only the epistemological significance of immediate, rational evidence.
These two meanings are peculiarly mingled in Descartes' proofs for the existence of God, which form an integrant constituent of his theory of knowledge, in so far as this "idea" is the first for which,
in the synthetic procedure of his method a clearness and distinct ness or intuitive evidence of the " natural light," equal to that of self-consciousness, is claimed. The new (so-called Cartesian) proof which he introduces in this connection," has a multitude of scholastic
> Resp. ad Obj. II. i Princ. Phil. I. 45.
8 [German Idee. I follow the ordinary English usage in spelling the word as used by Descartes without a capital. ]
4 Cf. E. Grimm, D. 's Lehre ron den angeborenen Ideen (Jena, 1873), and also P. Natorp, Z>. '« Erkenntnisstheorie (Marburg, 1882). That in nut us is better translated by eingeboren than by the usual angeboren has been remarked by R. Eucken, Qeachichte und Kritik der Grundbegriffe der Oegenwart, p. 73.
* Med.
