No More Learning

* On the other hand,
a requirement of pure practical reason is based on a duty, that of
making something (the summum bonum) the object of my will so as to
promote it with all my powers; in which case I must suppose its
possibility and, consequently, also the conditions necessary
thereto, namely, God, freedom, and immortality; since I cannot prove
these by my           reason, although neither can I refute them.