Not sure if Plotinus counts as an Ancient Greek philosopher, since he was born in Egypt (Aegyptus - then part of the Roman Empire), but, like Marcus Aurelius, he wrote in Greek, so I'm posting this here.
Anyway, I was reading Plotinus on dialectic (Enneads vol I, tract 3) and found it very interesting from a post-Hegelian perspective:
(Scroll down to #4 for the specific discussion of dialectic.)
ON DIALECTIC (The Upward Way)
1. What art is there, what method, what discipline to bring us there where we must go?
The Term at which we must arrive we may take as agreed: we have established elsewhere, by many considerations, that our journey is to the Good, to the Primal-Principle; and, indeed, the very reasoning which discovered the Term was itself something like an initiation.
But what order of beings will attain the Term?
Surely, as we read, those that have already seen all or most things, those who at their first birth have entered into the life-germ from which is to spring a metaphysician, a musician or a born lover, the metaphysician taking to the path by instinct, the musician and the nature peculiarly susceptible to love needing outside guidance.
But how lies the course? Is it alike for all, or is there a distinct method for each class of temperament?
For all there are two stages of the path, as they are making upwards or have already gained the upper sphere.
The first degree is the conversion from the lower life; the second- held by those that have already made their way to the sphere of the Intelligibles, have set as it were a footprint there but must still advance within the realm- lasts until they reach the extreme hold of the place, the Term attained when the topmost peak of the Intellectual realm is won.
But this highest degree must bide its time: let us first try to speak of the initial process of conversion.
We must begin by distinguishing the three types. Let us take the musician first and indicate his temperamental equipment for the task.
The musician we may think of as being exceedingly quick to beauty, drawn in a very rapture to it: somewhat slow to stir of his own impulse, he answers at once to the outer stimulus: as the timid are sensitive to noise so he to tones and the beauty they convey; all that offends against unison or harmony in melodies and rhythms repels him; he longs for measure and shapely pattern.
This natural tendency must be made the starting-point to such a man; he must be drawn by the tone, rhythm and design in things of sense: he must learn to distinguish the material forms from the Authentic-Existent which is the source of all these correspondences and of the entire reasoned scheme in the work of art: he must be led to the Beauty that manifests itself through these forms; he must be shown that what ravished him was no other than the Harmony of the Intellectual world and the Beauty in that sphere, not some one shape of beauty but the All-Beauty, the Absolute Beauty; and the truths of philosophy must be implanted in him to lead him to faith in that which, unknowing it, he possesses within himself. What these truths are we will show later.
2. The born lover, to whose degree the musician also may attain- and then either come to a stand or pass beyond- has a certain memory of beauty but, severed from it now, he no longer comprehends it: spellbound by visible loveliness he clings amazed about that. His lesson must be to fall down no longer in bewildered delight before some, one embodied form; he must be led, under a system of mental discipline, to beauty everywhere and made to discern the One Principle underlying all, a Principle apart from the material forms, springing from another source, and elsewhere more truly present. The beauty, for example, in a noble course of life and in an admirably organized social system may be pointed out to him- a first training this in the loveliness of the immaterial- he must learn to recognise the beauty in the arts, sciences, virtues; then these severed and particular forms must be brought under the one principle by the explanation of their origin. From the virtues he is to be led to the Intellectual-Principle, to the Authentic-Existent; thence onward, he treads the upward way.
3. The metaphysician, equipped by that very character, winged already and not like those others, in need of disengagement, stirring of himself towards the supernal but doubting of the way, needs only a guide. He must be shown, then, and instructed, a willing wayfarer by his very temperament, all but self-directed.
Mathematics, which as a student by nature he will take very easily, will be prescribed to train him to abstract thought and to faith in the unembodied; a moral being by native disposition, he must be led to make his virtue perfect; after the Mathematics he must be put through a course in Dialectic and made an adept in the science.
4. But this science, this Dialectic essential to all the three classes alike, what, in sum, is it?
It is the Method, or Discipline, that brings with it the power of pronouncing with final truth upon the nature and relation of things - what each is, how it differs from others, what common quality all have, to what Kind each belongs and in what rank each stands in its Kind and whether its Being is Real-Being, and how many Beings there are, and how many non-Beings to be distinguished from Beings.
Dialectic treats also of the Good and the not-Good, and of the particulars that fall under each, and of what is the Eternal and what the not Eternal- and of these, it must be understood, not by seeming-knowledge ["sense-knowledge"] but with authentic science.
All this accomplished, it gives up its touring of the realm of sense and settles down in the Intellectual Kosmos and there plies its own peculiar Act: it has abandoned all the realm of deceit and falsity, and pastures the Soul in the "Meadows of Truth": it employs the Platonic division to the discernment of the Ideal-Forms, of the Authentic-Existence and of the First-Kinds [or Categories of Being]: it establishes, in the light of Intellection, the unity there is in all that issues from these Firsts, until it has traversed the entire Intellectual Realm: then, resolving the unity into the particulars once more, it returns to the point from which it starts.
Now rests: instructed and satisfied as to the Being in that sphere, it is no longer busy about many things: it has arrived at Unity and it contemplates: it leaves to another science all that coil of premisses and conclusions called the art of reasoning, much as it leaves the art of writing: some of the matter of logic, no doubt, it considers necessary- to clear the ground- but it makes itself the judge, here as in everything else; where it sees use, it uses; anything it finds superfluous, it leaves to whatever department of learning or practice may turn that matter to account.
5. But whence does this science derive its own initial laws?
The Intellectual-Principle furnishes standards, the most certain for any soul that is able to apply them. What else is necessary, Dialectic puts together for itself, combining and dividing, until it has reached perfect Intellection. "For," we read, "it is the purest [perfection] of Intellection and Contemplative-Wisdom." And, being the noblest method and science that exists it must needs deal with Authentic-Existence, The Highest there is: as Contemplative-Wisdom [or true-knowing] it deals with Being, as Intellection with what transcends Being.
What, then, is Philosophy?
Philosophy is the supremely precious.
Is Dialectic, then, the same as Philosophy?
It is the precious part of Philosophy. We must not think of it as the mere tool of the metaphysician: Dialectic does not consist of bare theories and rules: it deals with verities; Existences are, as it were, Matter to it, or at least it proceeds methodically towards Existences, and possesses itself, at the one step, of the notions and of the realities.
Untruth and sophism it knows, not directly, not of its own nature, but merely as something produced outside itself, something which it recognises to be foreign to the verities laid up in itself; in the falsity presented to it, it perceives a clash with its own canon of truth. Dialectic, that is to say, has no knowledge of propositions- collections of words- but it knows the truth, and, in that knowledge, knows what the schools call their propositions: it knows above all, the operation of the soul, and, by virtue of this knowing, it knows, too, what is affirmed and what is denied, whether the denial is of what was asserted or of something else, and whether propositions agree or differ; all that is submitted to it, it attacks with the directness of sense-perception and it leaves petty precisions of process to what other science may care for such exercises.
6. Philosophy has other provinces, but Dialectic is its precious part: in its study of the laws of the universe, Philosophy draws on Dialectic much as other studies and crafts use Arithmetic, though, of course, the alliance between Philosophy and Dialectic is closer.
And in Morals, too, Philosophy uses Dialectic: by Dialectic it comes to contemplation, though it originates of itself the moral state or rather the discipline from which the moral state develops.
Our reasoning faculties employ the data of Dialectic almost as their proper possession for they are mainly concerned about Matter [whose place and worth Dialectic establishes].
And while the other virtues bring the reason to bear upon particular experiences and acts, the virtue of Wisdom [i.e., the virtue peculiarly induced by Dialectic] is a certain super-reasoning much closer to the Universal; for it deals with correspondence and sequence, the choice of time for action and inaction, the adoption of this course, the rejection of that other: Wisdom and Dialectic have the task of presenting all things as Universals and stripped of matter for treatment by the Understanding.
But can these inferior kinds of virtue exist without Dialectic and philosophy?
Yes- but imperfectly, inadequately.
And is it possible to be a Sage, Master in Dialectic, without these lower virtues?
It would not happen: the lower will spring either before or together with the higher. And it is likely that everyone normally possesses the natural virtues from which, when Wisdom steps in, the perfected virtue develops. After the natural virtues, then, Wisdom and, so the perfecting of the moral nature. Once the natural virtues exist, both orders, the natural and the higher, ripen side by side to their final excellence: or as the one advances it carries forward the other towards perfection.
But, ever, the natural virtue is imperfect in vision and in strength- and to both orders of virtue the essential matter is from what principles we derive them.
Extracted from: The Six Enneads by Plotinus, translated by Stephen Mackenna (1917)