FORE:Before entering on our task of reconstruction, we must turn aside to consider with what success the same enterprise has been attempted by modern German criticism, especially by its chief contemporary representative, the last and most distinguished historian of Greek philosophy. The result at which Zeller, following Schleiermacher, arrives is that the great achievement of Socrates was to put forward an adequate idea of knowledge; in other words, to show what true science ought to be, and what, as yet, it had never been, with the addition of a demand that all action should be based on such a scientific knowledge as its only sure foundation.87 To know a thing was to know its essence, its concept, the assemblage of qualities which together constitute its definition, and make it to be what it is. Former thinkers had also sought for knowledge, but not as knowledge, not with a clear notion of what it was that they really wanted. Socrates, on the other hand, required that men should always be prepared to give a strict account of the end which they had in view, and of the means by which they hoped to gain it. Further, it had been customary to single out for exclusive attention that quality of an object by which the observer happened to be most strongly impressed, passing over all the others; the consequence of which was that the philosophers had taken a one-sided view of facts, with the result of falling into hopeless disagreement among themselves; the Sophists had turned these contradictory points of view against one another, and thus effected their mutual destruction; while the dissolution of objective certainty had led to a corresponding dissolution of moral truth. Socrates accepts the Sophistic scepticism so far as it applies to the existing state of science, but does not push it to the same fatal con118clusion; he grants that current beliefs should be thoroughly sifted and, if necessary, discarded, but only that more solid convictions may be substituted for them. Here a place is found for his method of self-examination, and for the self-conscious ignorance attributed to him by Plato. Comparing his notions on particular subjects with his idea of what knowledge in general ought to be, he finds that they do not satisfy it; he knows that he knows nothing. He then has recourse to other men who declare that they possess the knowledge of which he is in search, but their pretended certainty vanishes under the application of his dialectic test. This is the famous Socratic irony. Finally, he attempts to come at real knowledge, that is to say, the construction of definitions, by employing that inductive method with the invention of which he is credited by Aristotle. This method consists in bringing together a number of simple and familiar examples from common experience, generalising from them, and correcting the generalisations by comparison with negative instances. The reasons that led Socrates to restrict his enquiries to human interests are rather lightly passed over by Zeller; he seems at a loss how to reconcile the alleged reform of scientific method with the complete abandonment of those physical investigations which, we are told, had suffered so severely from being cultivated on a different system.
THREE:Next to its bearing on the question of immortality, the Epicurean psychology is most interesting as a contribution to the theory of cognition. Epicurus holds that all our knowledge is derived from experience, and all our experience, directly or indirectly, from the presentations of sense. So far he says no more than would be admitted by the Stoics, by Aristotle, and indeed by every Greek philosopher except Plato. There is, therefore, no necessary connexion between his views in this respect and his theory of ethics, since others had combined the same views with a very different standard of action. It is in discussing the vexed question of what constitutes the ultimate criterion of truth that he shows to most disadvantage in comparison with the more intellectual96 schools. He seems to have considered that sensation supplies not only the matter but the form of knowledge; or rather, he seems to have missed the distinction between matter and form altogether. What the senses tell us, he says, is always true, although we may draw erroneous inferences from their statements.184 But this only amounts to the identical proposition that we feel what we feel; for it cannot be pretended that the order of our sensations invariably corresponds to the actual order of things in themselves. Even confining ourselves to individual sensations, or single groups of sensations, there are some that do not always correspond to the same objective reality, and others that do not correspond to any reality at all; while, conversely, the same object produces a multitude of different sensations according to the subjective conditions under which it affects us. To escape from this difficulty, Epicurus has recourse to a singularly crude theory of perception, borrowed from Empedocles and the older atomists. What we are conscious of is, in each instance, not the object itself, but an image composed of fine atoms thrown off from the surfaces of bodies and brought into contact with the organs of sense. Our perception corresponds accurately to an external image, but the image itself is often very unlike the object whence it originally proceeded. Sometimes it suffers a considerable change in travelling through the atmosphere. For instance, when a square tower, seen at a great distance, produces the impression of roundness, this is because the sharp angles of its image have been rubbed off on the way to our eyes. Sometimes the image continues to wander about after its original has ceased to exist, and that is why the dead seem to revisit us in our dreams. And sometimes the images of different objects coalesce as they are floating about, thus producing the appearance of impossible monsters, such as centaurs and chimaeras.185
THREE:"I am absolutely certain of it. I took you for a dreamer. I argued that if I used this thing you would not be an atom the wiser. People who talk so much about their own work as you do are generally very foolish."
