337. In concluding this book, I wish to give a summary of my views on certainty, wherein I shall show the connection between the doctrines exposed in the different chapters.
When philosophy meets a necessary fact its duty is to accept it. Such a fact is certainty. To dispute its existence, is to dispute the splendor of the sun at mid-day. Mankind are certain of many things; philosophers, skeptics not excluded, are equally so. Absolute skepticism is impossible.
Setting aside the question of certainty, philosophy is free from extravagance, and is established in the domain of reason; it can there examine how we acquire certainty, and upon what it is based.
The human race is endowed with certainty as a quality annexed to life, a spontaneous result of the development of the soul's faculties. Certainty is natural; consequently it precedes all philosophy, and is independent of the opinions of men. For the same reason the question of certainty, although important to the knowledge of the laws to which our mind is subject, is, and always will be, unproductive of practical results. It is a dividing line fixed by reason lest at any time something should descend from the realm of abstraction prejudicial to society or individuals. Thus from its first investigations, philosophy forms a kind of alliance with good sense; they mutually promise never to be hostile to each other.
When we examine the foundations of certainty a question arises upon the first principle of human cognitions: does it exist, and what is it?
This question may have a double meaning. It may either mean a primitive truth containing all others, as the seed does plants and fruits; or simply a resting-point. The former gives rise to the question of transcendental science; the latter is the cause of the disputes in the schools on the preference of different truths in relation to the dignity of first principle.
If truth exists, there must be means of knowing it, hence the question of the value of criteria.
There is in the order of being one truth, the origin of all truths, God, who is also in the absolute intellectual order the origin of all truths. In the human intellectual order there is no one truth, the origin of all others; neither is there in the real, nor in the ideal order. The philosophy of the me can be of no account in establishing transcendental science. The doctrine of absolute identity is an absurdity; besides, it explains nothing.
The problem of representation is here proposed. The representation may be of identity, causality, or ideality. The last is founded on the preceding, but is distinct from it.