5. Whence does this science derive its proper principles? Intelligence furnishes the soul with the clear principles she is capable of receiving. Having discovered and achieved these principles, dialectics puts their consequences in order. Dialectics composes, and divides, till it has arrived at a perfect intelligence of things; for according to (Plato),[350] dialectics is the purest application of intelligence and wisdom. In this case, if dialectics be the noblest exercise of our faculties, it must exercise itself with essence and the highest objects. Wisdom studies existence, as intelligence studies that which is still beyond existence (the One, or the Good). But is not philosophy also that which is most eminent? Surely. But there is no confusion between philosophy and dialectics, because dialectics is the highest part of philosophy. It is not (as Aristotle thought) merely an instrument for philosophy, nor (as Epicurus thought) made up of pure speculations and abstract rules. It studies things themselves, and its matter is the (real) beings. It reaches them by following a method which yields reality as well as the idea. Only accidentally does dialectics busy itself with error and sophisms. Dialectics considers them alien to its mission, and as produced by a foreign principle. Whenever anything contrary to the rule of truth is advanced, dialectics recognizes the error by the light of the truths it contains. Dialectics, however, does not care for propositions, which, to it, seem only mere groupings of letters. Nevertheless, because it knows the truth, dialectics also understands propositions, and, in general, the operations of the soul. Dialectics knows what it is to affirm, to deny, and how to make contrary or contradictory assertions. Further, dialectics distinguishes differences from identities, grasping the truth by an intuition that is as instantaneous as is that of the senses; but dialectics leaves to another science, that enjoys those details, the care of treating them with exactness. THE VARIOUS BRANCHES OF PHILOSOPHY CROWNED BY DIALECTICS.