In this, the profoundest of subjects, we always find in Plato light for the way. Although he has not given us complete examples, yet he has pointed out the road of the true Speculative method in a way not to be mistaken. Instead of setting out with first principles presupposed as true, by which all is to be established, (as mathematics and such sciences do), he asserts that the first starting points must be removed as inadequate. We begin with the immediate, which is utterly insufficient, and exhibits itself as such. We ascend to a more adequate, by removing the first hypothesis; and this process repeats itself until we come to the first principle, which of course bears its own evidence in this, that it is absolutely universal and absolutely determined at the same time; in other words it is the self-determining, the “self-moved,” as Plato and Aristotle call it. It is its own other, and hence it is the true infinite, for it is not limited but continued by its other. From this peculiarity results the difficulty of Speculative Philosophy. The unused mind, accepting with naïveté the first proposition as settled, finds itself brought into confusion when this is contradicted, and condemns the whole procedure. The irony of Socrates, that always begins by positing the ground of his adversary, and reducing it through its own inadequateness to contradict itself, is of this character, and the unsophisticated might say, and do say: “See how illogical is Socrates, for he sets out to establish something, and arrives rather at the destruction of it.” The _reductio ad absurdum_ is a faint imitation of the same method. It is not sufficient to prove your own system by itself, for each of the opposing systems can do that; but you must show that any and all counter-hypotheses result in your own. God makes the wrath of men to praise Him, and all imperfect things must continually demonstrate the perfect, for the reason that they do not exist by reason of their defects, but through what of truth there is in them, and the imperfection is continually manifesting the _want_ of the perfect. “Spirit,” says Hegel, “is self-contained being. But matter, which is spirit outside of itself, [turned inside out,] continually manifests this, its inadequacy, through gravity—attraction to a central point beyond each particle. (If it could get at this central point, it would have no extension, and hence would be annihilated.)” The soul of this method lies in the comprehension of the negative. In that wonderful exposé of the importance of the negative, which Plato gives in the Parmenides and Sophist, we see how justly he appreciated its true place in Philosophic Method. Spinoza’s “_omnis determinatio est negatio_” is the most famous of modern statements respecting the negative, and has been very fruitful in results.