PROP. VI.————
The coincidence of the known and the existent must be proved, not guessed at.sublimest lesson she can teach. To this end all her labours are directed, all her instructions minister. To prove it, is to reach the truth. But the coincidence of the known and the existent—the equation of Knowing and Being—is not to be assumed: it is not enough merely to surmise it. Its exhibition must be reasoned, and this reasoning is the most delicate, as well as the most extensive operation in metaphysics. It is indeed nothing less than the whole length of that dialectical chain, the laying out of whose separate links in an unbroken sequence of demonstrated propositions is the end which these institutes have in view. And this undertaking can be carried to a successful issue only by an ascertainment of the conditions on which alone any knowledge is possible—no respect being paid, in the first instance, and pending that preliminary inquisition, to anything which may be supposed to exist.
Plato's deficiencies.11. Here it was that Plato broke down. Instead of proving the coincidence of the known and the existent, he assumed it. But this assumption did not require the genius of a Plato: any man could have assumed it. What was wanted was its demonstration: for unreasoned truth is an alien from philosophy, although it may not be an outcast from humanity. But this proof Plato did not supply. His method, indeed, or rather want of method, rendered anything like a demonstration impossible. For the