WHAT DIALECTICS IS.
4. What then is this dialectics, knowledge of which must be added to mathematics? It is a science which makes us capable of reasoning about each thing, to say what it is, in what it differs from the others, in what it resembles them, where it is, whether it be one of the beings, to determine how many veritable beings there are, and which are the objects that contain nonentity instead of veritable essence. This science treats also of good and evil; of everything that is subordinated to (being), the Good, and to its contrary; of the nature of what is eternal, and transitory. It treats of each matter scientifically, and not according to mere opinion. Instead of wandering around the sense-world, it establishes itself in the intelligible world; it concentrates its whole attention on this world, and after having saved our soul from deceit, dialectics "pastures our soul in the meadow of truth,"[347] (as thought Plato). Then it makes use of the Platonic method of division to discern ideas, to define each object, to rise to the several kinds of essences[348] (as thought Plato); then, by thought concatenating all that is thence derived, dialectics continues its deductions until it has gone through the whole domain of the intelligible. Then, by reversing, dialectics returns to the very Principle from which first it had started out.[349] Resting there, because it is only in the intelligible world that it can find rest, no longer needing to busy itself with a multitude of objects, because it has arrived at unity, dialectics considers its logic, which treats of propositions and arguments. This logic is an art subordinate to dialectics just as writing is subordinate to thought. In logic, dialectics recognizes some principles as necessary, and others as constituting preparatory exercises. Then, along with everything else, subjecting these principles to its criticism, it declares some of them useful, and others superfluous, or merely technical.
DIALECTICS IS THE HIGHEST PART OF PHILOSOPHY.
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.
6. Dialectics, therefore, is only one part of philosophy, but the most important. Indeed, philosophy has other branches. First, it studies nature (in physics), therein employing dialectics, as the other arts employ arithmetic, though philosophy owes far more to dialectics. Then philosophy treats of morals, and here again it is dialectics that ascertains the principles; ethics limits itself to building good habits thereon, and to propose the exercises that shall produce those good habits. The (Aristotelian) rational virtues also owe to dialectics the principles which seem to be their characteristics; for they chiefly deal with material things (because they moderate the passions). The other virtues[351] also imply the application of reason to the passions and actions which are characteristic of each of them. However, prudence applies reason to them in a superior manner. Prudence deals rather with the universal, considering whether the virtues concatenate, and whether an action should be done now, or be deferred, or be superseded by another[352] (as thought Aristotle). Now it is dialectics, or its resultant science of wisdom which, under a general and immaterial form, furnishes prudence with all the principles it needs.
WITHOUT DIALECTICS LOWER KNOWLEDGE WOULD BE IMPERFECT.
Could the lower knowledge not be possessed without dialectics or wisdom? They would, at least, be imperfect and mutilated. On the other hand, though the dialectician, that is, the true sage, no longer need these inferior things, he never would have become such without them; they must precede, and they increase with the progress made in dialectics. Virtues are in the same case. The possessor of natural virtues may, with the assistance of wisdom, rise to perfect virtues. Wisdom, therefore, only follows natural virtues. Then wisdom perfects the morals. Rather, the already existing natural virtues increase and grow perfect along with wisdom. Whichever of these two things precedes, complements the other. Natural virtues, however, yield only imperfect views and morals; and the best way to perfect them, is philosophic knowledge of the principles from which they depend.