c. In that Plato places truth in that alone which is produced through thought, and yet the source of knowledge is manifold—in feelings, sensations, &c.—we must state the different kinds of knowledge, as given by Plato. Plato is entirely opposed to the idea that the truth is given through sensuous consciousness, which is what is known and that from which we start; for this is the doctrine of the Sophists with which we met in dealing with Protagoras, for instance. As regards feeling, we easily make the mistake of placing everything in feeling, as indeed that Platonic rage for beauty contained the truth in the guise of feeling; but this is not the true form of the truth, because feeling is the entirely subjective consciousness. Feeling as such is merely a form with which men make the arbitrary will the principle of the truth, for what is the true content is not given through feeling; in it every content has a place. The highest content must likewise be found in feeling; to have a thing in thought and understanding is quite different from having it in heart and feeling, i.e. in our most inward subjectivity, in this “I”; and we say of the content that it is for the first time in its proper place when it is in the heart, because it then is entirely identical with our individuality. The mistake, however, is to say that a content is true because it is in our feeling. Hence the importance of Plato’s doctrine that the content becomes filled by thought alone; for it is the universal which can be grasped by the activity of thought alone. Plato has defined this universal content as Idea.
At the close of the sixth book of the Republic (pp. 509-511 Steph.; pp. 321-325 Bekk.) Plato distinguishes the sensuous and the intellectual in our knowledge more exactly, so that in each sphere he again presents two modes of consciousness. “In the sensuous (ὁρατόν) the one division is the external manifestation, for in it are shadows, reflections in water, and also in solid, smooth, and polished bodies, and the like. The second section, of which this is only the resemblance, includes animals, plants” (this concrete life), “and everything in art. The intelligible (νοητόν) is also divided into two parts. In the one sub-division the soul uses the sensuous figures given before, and is obliged to work on hypotheses (ἐξ ὑποθέσεων) because it does not go to the principle but to the result.” Reflection, which is not on its own account sensuous, but undoubtedly belongs to thought, mingles thought with the first sensuous consciousness, although its object is not as yet a pure existence of the understanding. “The other division” (what is thought in the soul itself) “is that in which the soul, proceeding from an hypothesis, makes its way (μέθοδον) to a principle which is above hypotheses, not by means of images, as in the former cases, but through the ideas themselves. Those who study geometry, arithmetic, and kindred sciences, assume the odd and the even, the figures, three kinds of angles, and the like. And since they start from these hypotheses, they do not think it necessary to give any account of them, for everybody is supposed to know them. You further know that they make use of figures which are risible, and speak of them, although they are not thinking of them, but of the ideals which they represent; for they think of the” (absolute) “square itself and of its diagonals, and not of the” (sensuous) “images that they draw. And so it is with other things.” Thus, according to Plato, this is certainly the place where real knowledge begins, because we have nothing further to do with the sensuous as such; at the same time this is not the true knowledge which considers the spiritual universal on its own account, but the arguing and reasoning knowledge that forms universal laws and particular kinds or species out of what is sensuous. “These figures which they draw or make, and which also have shadows and images in water, they use only as images, and seek to behold their originals, which can only be seen with the understanding” (διανοίᾳ).—“That is true.”—“This I have named above that species of the intelligible, in inquiring into which the soul is compelled to use hypotheses, not proceeding to a first principle, because it is not able to get above those hypotheses, but employing those secondary images as images which are made absolutely similar to the originals in every respect”—“I understand that you are speaking of geometry and the kindred arts”—“Now learn about the other division of the intelligible in which reason (λόγος) itself is concerned, since by the power of the dialectic it makes use of hypotheses, not as principles but only as hypotheses—that is to say, as steps and points of departure in order to reach a region above hypotheses, the first principle of all” (which is in and for itself), “and clinging to this and to that which depends on this, it descends again to the result, for it requires no sensuous aid at all, but only ideas, and thus it reaches the ideas finally through the ideas themselves.” To know this is the interest and business of Philosophy; this is investigated by pure thought in and for itself, which only moves in such pure thoughts. “I understand you, but not perfectly. You seem to me to wish to assert that what is contemplated in Being and Knowledge through the science of dialectic is clearer than what is contemplated by the so-called sciences which have hypotheses as their principle, and where those who contemplate them have to do so with the understanding and not with the senses. Yet because in their contemplation they do not ascend to the absolute principle, but speculate from hypotheses, they appear not to exercise thought (νοῦν) upon these objects, although these objects are cognizable by thought if a principle is added to them (νοητῶν ὄντων μετὰ ἀρχῆς). The methods (ἕξιν) of geometry and its kindred sciences you appear to me to call understanding; and that because it stands midway between reason (νοῦς) and ‘sensuous’ opinion (δόξα).”—“You have quite grasped my meaning. Corresponding to these four sections, I will suppose four faculties (παθήματα) in the soul—conceiving reason (νόησις) has the highest place (ἐπὶ τῷ ἀνωτάτῳ), understanding the second; the third is called faith (πίστις)”—the true conception for animals and plants in that they are living, homogeneous and identical with ourselves; “and the last the knowledge of images (εἰκασία),” opinion. “Arrange them according to the fact that each stage has as much clearness (σαφηνείας) as that to which it is related has truth.” This is the distinction which forms the basis of Plato’s philosophy, and which came to be known from his writings.
Now if we go from knowledge to its content, in which the Idea becomes sundered, and thereby organizes itself more completely into a scientific system, this content, according to Plato, begins to fall into three parts which we distinguish as the logical, natural, and mental philosophy. The logical Philosophy the ancients called dialectic, and its addition to philosophy is by the ancient writers on the subject ascribed to Plato (Vol. I. p. 387). This is not a dialectic such as we met with in the Sophists, which merely brings one’s ideas altogether into confusion, for this first branch of Platonic philosophy is the dialectic which moves in pure Notions—the movement of the speculatively logical, with which several dialogues, and particularly that of Parmenides, occupy themselves. The second, according to Plato, is a kind of natural philosophy, the principles of which are more especially propounded in the Timæus. The third is the philosophy of the mind—an ethical philosophy—and its representation is essentially that of a perfect state in the Republic. The Critias should be taken in connection with the Timæus and the Republic, but we need not make further reference to it, for it is only a fragment. Plato makes these three dialogues one connected conversation. In the Critias and the Timæus the subject is so divided that while the Timæus dealt with the speculative origin of man and of nature, the Critias was intended to represent the ideal history of human culture, and to be a philosophical history of the human race, forming the ancient history of the Athenians as preserved by the Egyptians. Of this, however, only the beginning has come down to us.[29] Hence if the Parmenides be taken along with the Republic and the Timæus, the three together constitute the whole Platonic system of philosophy divided into its three parts or sections. We now wish to consider the philosophy of Plato more in detail in accordance with these three different points of view.
We have already remarked by way of preparation that the Notion of true dialectic is to show forth the necessary movement of pure Notions, without thereby resolving these into nothing; for the result, simply expressed, is that they are this movement, and the universal is just the unity of these opposite Notions. We certainly do not find in Plato a full consciousness that this is the nature of dialectic, but we find dialectic itself present; that is, we find absolute existence thus recognized in pure Notions, and the representation of the movement of these Notions. What makes the study of the Platonic dialectic difficult is the development and the manifestation of the universal out of ordinary conceptions. This beginning, which appears to make knowledge easier, really makes the difficulty greater, since it introduces us into a field in which there is quite a different standard from what we have in reason, and makes this field present to us; when, on the contrary, progression and motion take place in pure Notions alone, the other is not remembered at all. But in that very way the Notions attain greater truth. For otherwise pure logical movement might easily appear to us to exist on its own account, like a private territory, which has another region alongside of it, also having its own particular place. But since both are there brought together, the speculative element begins to appear as it is in truth; that is, as being the only truth, and that, indeed, through the transformation of sensuous opinion into thought. For in our consciousness we first of all find the immediate individual, the sensuous real; or there are also categories of the understanding which are held by us to be ultimate and true. But contrasted with merely external reality, it is rather the ideal that is the most real, and it was Plato who perceived that it was the only real, for he characterized the universal or thought as the true, in opposition to what is sensuous.
Thus the aim of many of Plato’s Dialogues, which conclude without any positive affirmation (Vol. I. p. 406; II. p. 13), is to show that the immediately existent, the many things that appear to us, although we may have quite true conceptions of them, are still not in themselves, in an objective sense, the true, because they alter and are determined through their relation to something else and not through themselves; thus we must even in the sensuous individuals consider the universal, or what Plato has called the Idea (p. 29). The sensuous, limited, and finite is, in fact, both itself and the other, which is also considered as existent; and thus there is an unsolved contradiction, for the other has dominion in the first. We have been before reminded (Vol. I. p. 404; II. p. 33) that the aim of the Platonic dialectic is to confuse and to resolve the finite ideas of men, in order to bring about in their consciousness what science demands, the consideration of that which is. By being thus directed against the form of the finite, dialectic has in the first place the effect of confounding the particular, and this is brought about by the negation therein present being shown forth, so that, in fact, it is proved that it is not what it is, but that it passes into its opposite, into the limitations which are essential to it. But if this dialectic is laid hold of, the particular passes away and becomes another than that which it is taken to be. Formal philosophy cannot look at dialectic in any other way than as being the art of confusing ordinary conceptions or even Notions, and demonstrating their nullity, thus making their result to be merely negative. For this reason, Plato in his Republic (VII. pp. 538, 539, Steph.; pp. 370, 371, Bekk.) advised the citizens not to allow dialectic to be studied before the thirtieth year, because by its means anyone might transform the beautiful, as he had received it from his masters, into that which is hateful. We find this dialectic a great deal in Plato, both in the more Socratic and moralizing dialogues, and in the many dialogues which relate to the conceptions of the Sophists in regard to science.
In connection with this, the second part of dialectic makes its first aim the bringing of the universal in men to consciousness, which, as we formerly remarked when speaking of Socrates (Vol. I. p. 398), was the main interest of Socratic culture. From this time on, we may look at such an aim as having been discarded, and simply remark that a number of Plato’s Dialogues merely aim at bringing to consciousness a general conception, such as we have without taking any trouble at all (Vol. I. pp. 403, 404); hence this prolixity on Plato’s part often wearies us. This dialectic is, indeed, also a movement of thought, but it is really only necessary in an external way and for reflecting consciousness, in order to allow the universal, what is in and for itself, unalterable and immortal, to come forth. Hence these first two sides of the dialectic, directed as they are towards the dissolution of the particular and thus to the production of the universal, are not yet dialectic in its true form: it is a dialectic which Plato has in common with the Sophists, who understood very well how to disintegrate the particular. A subject which Plato very often treats of with this end in view, is virtue, which he proves to be only one (Vol. I. pp. 405, 411), and thereby he makes the universal good emerge from the particular virtues.
Now because the universal which has emerged from the confusion of the particular, i.e. the true, beautiful and good, that which taken by itself is species, was at first undetermined and abstract, it is, in the third place, a principal part of Plato’s endeavours further to determine this universal in itself. This determination is the relation which the dialectic movement in thought bears to the universal, for through this movement the Idea comes to these thoughts which contain the opposites of the finite within themselves. For the Idea, as the self-determining, is the unity of these differences, and thus the determinate Idea. The universal is hence determined as that which resolves and has resolved the contradictions in itself, and hence it is the concrete in itself; thus this sublation of contradiction is the affirmative. Dialectic in this higher sense is the really Platonic; as speculative it does not conclude with a negative result, for it demonstrates the union of opposites which have annulled themselves. Here begins what is difficult for the understanding to grasp. The form of Plato’s methods being not yet, however, developed purely on its own account, this is the reason that his dialectic is still often merely reasoning, and that it proceeds from individual points of view and frequently remains without result. On the other hand, Plato’s own teaching is directed against this merely reasoning dialectic; yet we see that it gives him trouble properly to show forth the difference. The speculative dialectic which commences with him, is thus the most interesting but also the most difficult part of his work; hence acquaintance is not usually made with it when the Platonic writings are studied. Tennemann, for example, did not at all comprehend what was most important in the Platonic philosophy, and only gathered some of it together in the form of dry ontological determinations—for that was what he could comprehend. But it shows the greatest lack of intellect in a historian of Philosophy only to see in a great philosophic form whether there is anything yielding profit to himself or not.
What we have thus to deal with in the dialectic of Plato is the pure thought of reason, from which he very clearly distinguishes the understanding (διάνοια), (supra, p. 47). We may have thoughts about many things—if indeed, we do have thought at all—but this is not what Plato means. Plato’s true speculative greatness, and that through which he forms an epoch in the history of Philosophy, and hence in the history of the world, lies in the fuller determination of the Idea; this extension of knowledge is one which some centuries later constituted the main element in the ferment which took place in universal history, and in the transformation which the human mind passed through. This fuller determination may, from what has gone before, be understood thus: Plato first comprehended the Absolute as the Being of Parmenides, but as the Universal which, as species, is also end, i.e. which rules, penetrates, and produces the particular and manifold. Plato, however, had not yet developed this self-producing activity, and hence often stumbled into an external teleology. As the union of the preceding principles, Plato further led this Being into determinateness and into difference, as the latter is contained in the triad of Pythagorean number-determinations, and expressed the same in thought. That is, he grasped the Absolute as the unity of Being and non-being—in Becoming, as Heraclitus says—or of the one and the many,[30] &c. He further now took into the objective dialectic of Heraclitus the Eleatic dialectic, which is the external endeavour of the subject to show forth contradiction, so that in place of an external changing of things, their inward transition in themselves, i.e. in their Ideas, or, as they are here, in their categories, has come to pass out of and through themselves. Plato finally set forth the belief of Socrates, which the latter put forward in regard to the moral self-reflection of the subject only, as objective, as the Idea, which is both universal thought and the existent. The previous philosophies thus do not disappear because refuted by Plato, being absorbed in him.
In addition to Being and non-being, one and many, the unlimited and limiting are, for instance, likewise pure thoughts such as these, in whose absolute contemplation, from an all-embracing point of view, the Platonic investigation occupies itself. The purely logical and quite abstruse consideration of such objects certainly contrasts strongly with our conception of the beautiful, pleasing, and attractive content of Plato. Such consideration to him signifies all that is best in Philosophy, and it is that which he everywhere calls the true method of Philosophy, and the knowledge of the truth; in it he places the distinction between philosophers and Sophists. The Sophists on their part look at appearances, and these they obtain in opinion; this, indeed, implies thought, but not pure thought, or what is in and for itself. This is one reason why many turn from the study of Plato’s works unsatisfied. When we commence a Dialogue, we find, in the free Platonic method of composition, beautiful scenes in nature, a superb introduction (p. 14) that promises to lead us through flowery fields into Philosophy—and that the highest Philosophy, the Platonic. We meet with elevated thoughts, which are responded to more specially by youth, but these soon disappear. If at first we have allowed ourselves to be carried away by these bright scenes, they must now be all renounced, and as we have come to the real dialectic, and truly speculative, we must keep to the wearisome path, and allow ourselves to be pricked by the thorns and thistles of metaphysics. For behold, we then come to what is best and highest, to investigations respecting the one and many, Being and nothing; this was not what was anticipated, and men go quietly away, only wondering that Plato should seek knowledge here. From the most profound dialectic investigation, Plato then again proceeds to representations and images, to the description of dialogues amongst intelligent men. Thus in the Phædo, for example, which Mendelssohn has modernized and transformed into Wolffian metaphysics, the beginning and end are elevating and beautiful, and the middle deals with dialectic. Hence in making one’s way through Plato’s Dialogues very many mental qualities are called into play, and in their study we consequently ought to keep our minds open and free as regards the very various points of interest. If we read with interest what is speculative, we are apt to overlook what is most beautiful; if our interest lies in the elevation and culture of the mind, we forget the speculative element and find that it does not appeal to us. With some it is like the young man in the Bible, who had fulfilled his various duties, and who asked Christ what good thing he still had to do to become His follower. But when the Lord commanded him to sell what he had and give to the poor, the young man went away sorrowful; this was not what he had anticipated. Just in the same way many mean well as regards Philosophy; they study Fries, and heaven knows whom else. Their hearts are full of the true, good and beautiful; they would know and see what they ought to do, but their breasts swell with goodwill alone.