Metaphysics has as the proper object of its enquiries three ideas only: God, freedom, and immortality. - Immanuel Kant

Even if there never have been actions arising from such pure sources, what is at issue here is not whether this or that happened; that, instead, reason by itself and independently of all appearances commands what ought to happen; that, accordingly, actions of which the world has perhaps so far given no example, and whose very practicability might be very much doubted by one who bases everything on experience, are still inflexibly commanded by reason … because … duty … lies, prior to all experience, in the idea of a reason determing the will by means of apriori grounds.

All trades, arts, and handiwork have gained by division of labor, namely, when, instead of one man doing everything, each confines himself to a certain kind of work distinct from others in the treatment it requires, so as to be able to perform it with greater facility and in the greatest perfection.

The guidelines for achieving wisdom consist of three leading maxims: 1) Think for yourself; 2) (in communication with other people) Put yourself in the place of the other person; 3) Always think by remaining faithful to your own self.