There are indeed many old fallacies which linger among us, and new ones are constantly springing up. But they are not of the kind to which ancient logic can be usefully applied. The weapons of common sense, not the analytics of Aristotle, are needed for their overthrow. Nor is the use of the Aristotelian logic any longer natural to us. We no longer put arguments into the form of syllogisms like the schoolmen; the simple use of language has been, happily, restored to us. Neither do we discuss the nature of the proposition, nor extract hidden truths from the copula, nor dispute any longer about nominalism and realism. We do not confuse the form with the matter of knowledge, or invent laws of thought, or imagine that any single science furnishes a principle of reasoning to all the rest. Neither do we require categories or heads of argument to be invented for our use. Those who have no knowledge of logic, like some of our great physical philosophers, seem to be quite as good reasoners as those who have. Most of the ancient puzzles have been settled on the basis of usage and common sense; there is no need to reopen them. No science should raise problems or invent forms of thought which add nothing to knowledge and are of no use in assisting the acquisition of it. This seems to be the natural limit of logic and metaphysics; if they give us a more comprehensive or a more definite view of the different spheres of knowledge they are to be studied; if not, not. The better part of ancient logic appears hardly in our own day to have a separate existence; it is absorbed in two other sciences: (1) rhetoric, if indeed this ancient art be not also fading away into literary criticism; (2) the science of language, under which all questions relating to words and propositions and the combinations of them may properly be included.
To continue dead or imaginary sciences, which make no signs of progress and have no definite sphere, tends to interfere with the prosecution of living ones. The study of them is apt to blind the judgment and to render men incapable of seeing the value of evidence, and even of appreciating the nature of truth. Nor should we allow the living science to become confused with the dead by an ambiguity of language. The term logic has two different meanings, an ancient and a modern one, and we vainly try to bridge the gulf between them. Many perplexities are avoided by keeping them apart. There might certainly be a new science of logic; it would not however be built up out of the fragments of the old, but would be distinct from them—relative to the state of knowledge which exists at the present time, and based chiefly on the methods of Modern Inductive philosophy. Such a science might have two legitimate fields: first, the refutation and explanation of false philosophies still hovering in the air as they appear from the point of view of later experience or are comprehended in the history of the human mind, as in a larger horizon: secondly, it might furnish new forms of thought more adequate to the expression of all the diversities and oppositions of knowledge which have grown up in these latter days; it might also suggest new methods of enquiry derived from the comparison of the sciences. Few will deny that the introduction of the words “subject” and “object” and the Hegelian reconciliation of opposites have been “most gracious aids” to psychology, or that the methods of Bacon and Mill have shed a light far and wide on the realms of knowledge. These two great studies, the one destructive and corrective of error, the other conservative and constructive of truth, might be a first and second part of logic. Ancient logic would be the propaedeutic or gate of approach to logical science—nothing more. But to pursue such speculations further, though not irrelevant, might lead us too far away from the argument of the dialogue.
The “Euthydemus” is, of all the Dialogues of Plato, that in which he approaches most nearly to the comic poet. The mirth is broader, the irony more sustained, the contrast between Socrates and the two Sophists, although veiled, penetrates deeper than in any other of his writings. Even Thrasymachus, in the Republic, is at last pacified, and becomes a friendly and interested auditor of the great discourse. But in the “Euthydemus” the mask is never dropped; the accustomed irony of Socrates continues to the end …
Socrates narrates to Crito a remarkable scene in which he has himself taken part, and in which the two brothers, Dionysodorus and Euthydemus, are the chief performers. They are natives of Chios, who had settled at Thurii, but were driven out, and in former days had been known at Athens as professors of rhetoric and of the art of fighting in armour. To this they have now added a new accomplishment—the art
