The answer is, that in these and all other determinations of any notion we are attributing to it 'Not-being.' We went in search of Not-being and seemed to lose Being, and now in the hunt after Being we recover both. Not-being is a kind of Being, and in a sense co-extensive with Being. And there are as many divisions of Not-being as of Being. To every positive idea 'just,' 'beautiful,' and the like, there is a corresponding negative idea 'not-just,' 'not-beautiful,' and the like.
A doubt may be raised whether this account of the negative is really the true one. The common logicians would say that the 'not-just,' 'not-beautiful,' are not really classes at all, but are merged in one great class of the infinite or negative. The conception of Plato, in the days before logic, seems to be more correct than this. For the word 'not' does not altogether annihilate the positive meaning of the word 'just': at least, it does not prevent our looking for the 'not-just' in or about the same class in which we might expect to find the 'just.' 'Not-just is not-honourable' is neither a false nor an unmeaning proposition. The reason is that the negative proposition has really passed into an undefined positive. To say that 'not-just' has no more meaning than 'not-honourable' that is to say, that the two cannot in any degree be distinguished, is clearly repugnant to the common use of language.
The ordinary logic is also jealous of the explanation of negation as relation, because seeming to take away the principle of contradiction. Plato, as far as we know, is the first philosopher who distinctly enunciated this principle; and though we need not suppose him to have been always consistent with himself, there is no real inconsistency between his explanation of the negative and the principle of contradiction. Neither the Platonic notion of the negative as the principle of difference, nor the Hegelian identity of Being and Not-being, at all touch the principle of contradiction. For what is asserted about Being and Not-Being only relates to our most abstract notions, and in no way interferes with the principle of contradiction employed in the concrete. Because Not-being is identified with Other, or Being with Not-being, this does not make the proposition 'Some have not eaten' any the less a contradiction of 'All have eaten.'
The explanation of the negative given by Plato in the Sophist is a true but partial one; for the word 'not,' besides the meaning of 'other,' may also imply 'opposition.' And difference or opposition may be either total or partial: the not-beautiful may be other than the beautiful, or in no relation to the beautiful, or a specific class in various degrees opposed to the beautiful. And the negative may be a negation of fact or of thought (ou and me). Lastly, there are certain ideas, such as 'beginning,' 'becoming,' 'the finite,' 'the abstract,' in which the negative cannot be separated from the positive, and 'Being' and 'Not-being' are inextricably blended.
Plato restricts the conception of Not-being to difference. Man is a rational animal, and is not as many other things as are not included under this definition. He is and is not, and is because he is not. Besides the positive class to which he belongs, there are endless negative classes to which he may be referred. This is certainly intelligible, but useless. To refer a subject to a negative class is unmeaning, unless the 'not' is a mere modification of the positive, as in the example of 'not honourable' and 'dishonourable'; or unless the class is characterized by the absence rather than the presence of a particular quality.
Nor is it easy to see how Not-being any more than Sameness or Otherness is one of the classes of Being. They are aspects rather than classes of Being. Not-being can only be included in Being, as the denial of some particular class of Being. If we attempt to pursue such airy phantoms at all, the Hegelian identity of Being and Not-being is a more apt and intelligible expression of the same mental phenomenon. For Plato has not distinguished between the Being which is prior to Not-being, and the Being which is the negation of Not-being (compare Parm.).
But he is not thinking of this when he says that Being comprehends Not-being. Again, we should probably go back for the true explanation to the influence which the Eleatic philosophy exercised over him. Under 'Not-being' the Eleatic had included all the realities of the sensible world. Led by this association and by the common use of language, which has been already noticed, we cannot be much surprised that Plato should have made classes of Not-being. It is observable that he does not absolutely deny that there is an opposite of Being. He is inclined to leave the question, merely remarking that the opposition, if admissible at all, is not expressed by the term 'Not-being.'
On the whole, we must allow that the great service rendered by Plato to metaphysics in the Sophist, is not his explanation of 'Not-being' as difference. With this he certainly laid the ghost of 'Not-being'; and we may attribute to him in a measure the credit of anticipating Spinoza and Hegel. But his conception is not clear or consistent; he does not recognize the different senses of the negative, and he confuses the different classes of Not-being with the abstract notion. As the Pre-Socratic philosopher failed to distinguish between the universal and the true, while he placed the particulars of sense under the false and apparent, so Plato appears to identify negation with falsehood, or is unable to distinguish them. The greatest service rendered by him to mental science is the recognition of the communion of classes, which, although based by him on his account of 'Not-being,' is independent of it. He clearly saw that the isolation of ideas or classes is the annihilation of reasoning. Thus, after wandering in many diverging paths, we return to common sense. And for this reason we may be inclined to do less than justice to Plato, because the truth which he attains by a real effort of thought is to us a familiar and unconscious truism, which no one would any longer think either of doubting or examining.
IV. The later dialogues of Plato contain many references to contemporary philosophy. Both in the Theaetetus and in the Sophist he recognizes that he is in the midst of a fray; a huge irregular battle everywhere surrounds him (Theaet.). First, there are the two great philosophies going back into cosmogony and poetry: the philosophy of Heracleitus, supposed to have a poetical origin in Homer, and that of the Eleatics, which in a similar spirit he conceives to be even older than Xenophanes (compare Protag.). Still older were theories of two and three principles, hot and cold, moist and dry, which were ever marrying and being given in marriage: in speaking of these, he is probably referring to Pherecydes and the early Ionians. In the philosophy of motion there were different accounts of the relation of plurality and unity, which were supposed to be joined and severed by love and hate, some maintaining that this process was perpetually going on (e.g. Heracleitus); others (e.g. Empedocles) that there was an alternation of them. Of the Pythagoreans or of Anaxagoras he makes no distinct mention. His chief opponents are, first, Eristics or Megarians; secondly, the Materialists.
The picture which he gives of both these latter schools is indistinct; and he appears reluctant to mention the names of their teachers. Nor can we easily determine how much is to be assigned to the Cynics, how much to the Megarians, or whether the 'repellent Materialists' (Theaet.) are Cynics or Atomists, or represent some unknown phase of opinion at Athens. To the Cynics and Antisthenes is commonly attributed, on the authority of Aristotle, the denial of predication, while the Megarians are said to have been Nominalists, asserting the One Good under many names to be the true Being of Zeno and the Eleatics, and, like Zeno, employing their negative dialectic in the refutation of opponents. But the later Megarians also denied predication; and this tenet, which is attributed to all of them by Simplicius, is certainly in accordance with their over-refining philosophy. The 'tyros young and old,' of whom Plato speaks, probably include both. At any rate, we shall be safer in accepting the general description of them which he has given, and in not attempting to draw a precise line between them.
Of these Eristics, whether Cynics or Megarians, several characteristics are found in Plato:
1. They pursue verbal oppositions; 2. they make reasoning impossible by their over-accuracy in the use of language; 3. they deny predication; 4. they go from unity to plurality, without passing through the intermediate stages; 5. they refuse to attribute motion or power to Being; 6. they are the enemies of sense; whether they are the 'friends of ideas,' who carry on the polemic against sense, is uncertain; probably under this remarkable expression Plato designates those who more nearly approached himself, and may be criticizing an earlier form of his own doctrines. We may observe (1) that he professes only to give us a few opinions out of many which were at that time current in Greece; (2) that he nowhere alludes to the ethical teaching of the Cynics unless the argument in the Protagoras, that the virtues are one and not many, may be supposed to contain a reference to their views, as well as to those of Socrates; and unless they are the school alluded to in the Philebus, which is described as 'being very skilful in physics, and as maintaining pleasure to be the absence of pain.' That Antisthenes wrote a book called 'Physicus,' is hardly a sufficient reason for describing them as skilful in physics, which appear to have been very alien to the tendency of the Cynics.
The Idealism of the fourth century before Christ in Greece, as in other ages and countries, seems to have provoked a reaction towards Materialism. The maintainers of this doctrine are described in the Theaetetus as obstinate persons who will believe in nothing which they cannot hold in their hands, and in the Sophist as incapable of argument. They are probably the same who are said in the Tenth Book of the Laws to attribute the course of events to nature, art, and chance. Who they were, we have no means of determining except from Plato's description of them. His silence respecting the Atomists might lead us to suppose that here we have a trace of them. But the Atomists were not Materialists in the grosser sense of the term, nor were they incapable of reasoning; and Plato would hardly have described a great genius like Democritus in the disdainful terms which he uses of the Materialists. Upon the whole, we must infer that the persons here spoken of are unknown to us, like the many other writers and talkers at Athens and elsewhere, of whose endless activity of mind Aristotle in his Metaphysics has preserved an anonymous memorial.
V. The Sophist is the sequel of the Theaetetus, and is connected with the Parmenides by a direct allusion (compare Introductions to Theaetetus and Parmenides). In the Theaetetus we sought to discover the nature of knowledge and false opinion. But the nature of false opinion seemed impenetrable; for we were unable to understand how there could be any reality in Not-being. In the Sophist the question is taken up again; the nature of Not-being is detected, and there is no longer any metaphysical impediment in the way of admitting the possibility of falsehood. To the Parmenides, the Sophist stands in a less defined and more remote relation. There human thought is in process of disorganization; no absurdity or inconsistency is too great to be elicited from the analysis of the simple ideas of Unity or Being. In the Sophist the same contradictions are pursued to a certain extent, but only with a view to their resolution. The aim of the dialogue is to show how the few elemental conceptions of the human mind admit of a natural connexion in thought and speech, which Megarian or other sophistry vainly attempts to deny.
True to the appointment of the previous day, Theodorus and Theaetetus meet Socrates at the same spot, bringing with them an Eleatic Stranger, whom Theodorus introduces as a true philosopher. Socrates, half in jest, half in earnest, declares that he must be a god in disguise, who, as Homer would say, has come to earth that he may visit the good and evil among men, and detect the foolishness of Athenian wisdom. At any rate he is a divine person, one of a class who are hardly recognized on earth; who appear in divers forms now as statesmen, now as sophists, and are often deemed madmen. 'Philosopher, statesman, sophist,' says Socrates, repeating the words 'I should like to ask our Eleatic friend what his countrymen think of them; do they regard them as one, or three?'
The Stranger has been already asked the same question by Theodorus and Theaetetus; and he at once replies that they are thought to be three; but to explain the difference fully would take time. He is pressed to give this fuller explanation, either in the form of a speech or of question and answer. He prefers the latter, and chooses as his respondent Theaetetus, whom he already knows, and who is recommended to him by Socrates.
We are agreed, he says, about the name Sophist, but we may not be equally agreed about his nature. Great subjects should be approached through familiar examples, and, considering that he is a creature not easily caught, I think that, before approaching him, we should try our hand upon some more obvious animal, who may be made the subject of logical experiment; shall we say an angler? 'Very good.'
In the first place, the angler is an artist; and there are two kinds of art, productive art, which includes husbandry, manufactures, imitations; and acquisitive art, which includes learning, trading, fighting, hunting. The angler's is an acquisitive art, and acquisition may be effected either by exchange or by conquest; in the latter case, either by force or craft. Conquest by craft is called hunting, and of hunting there is one kind which pursues inanimate, and another which pursues animate objects; and animate objects may be either land animals or water animals, and water animals either fly over the water or live in the water. The hunting of the last is called fishing; and of fishing, one kind uses enclosures, catching the fish in nets and baskets, and another kind strikes them either with spears by night or with barbed spears or barbed hooks by day; the barbed spears are impelled from above, the barbed hooks are jerked into the head and lips of the fish, which are then drawn from below upwards. Thus, by a series of divisions, we have arrived at the definition of the angler's art.
And now by the help of this example we may proceed to bring to light the nature of the Sophist. Like the angler, he is an artist, and the resemblance does not end here. For they are both hunters, and hunters of animals; the one of water, and the other of land animals. But at this point they diverge, the one going to the sea and the rivers, and the other to the rivers of wealth and rich meadow-lands, in which generous youth abide. On land you may hunt tame animals, or you may hunt wild animals. And man is a tame animal, and he may be hunted either by force or persuasion; either by the pirate, man-stealer, soldier, or by the lawyer, orator, talker. The latter use persuasion, and persuasion is either private or public. Of the private practitioners of the art, some bring gifts to those whom they hunt: these are lovers. And others take hire; and some of these flatter, and in return are fed; others profess to teach virtue and receive a round sum. And who are these last? Tell me who? Have we not unearthed the Sophist?
But he is a many-sided creature, and may still be traced in another line of descent. The acquisitive art had a branch of exchange as well as of hunting, and exchange is either giving or selling; and the seller is either a manufacturer or a merchant; and the merchant either retails or exports; and the exporter may export either food for the body or food for the mind. And of this trading in food for the mind, one kind may be termed the art of display, and another the art of selling learning; and learning may be a learning of the arts or of virtue. The seller of the arts may be called an art-seller; the seller of virtue, a Sophist.