The sudden death of Professor Hobhouse on June 21, at the age of sixty-four years, at Alençon, Normandy, is a heavy loss to science and philosophy. He combined in a rare degree great powers of metaphysical speculation and synthesis with capacity for painstaking and detailed research in many fields of empirical science. He was one of the pioneers of comparative psychology; he developed a technique of the greatest value in the handling of the vast and chaotic data of anthropology; he laid the foundations of a scientific sociology; and he has attempted a synthesis of the results of his scientific and philosophical studies on a scale which must win for him a high place among the systematic thinkers of the world. As a teacher and a social leader he inspired love and reverence by the nobility of his thought and utterance, his passion for justice, his wise and tender humanity. Members of the Philosophical Institute have special cause to mourn his loss. When the Institute was founded in 1925, it was the unanimous wish of all connected with its foundation that Professor Hobhouse should be its chairman; and it has been a great piece of good fortune for the Institute to have had the benefit of his ripe wisdom and extensive experience during the first five years of its life.

Some modern thinkers have supposed that “cause” is an outworn notion, or at least that it is one of which modern science has no need. This is due mainly to the discovery that, while the scientist can give us general laws as to what in fact happens, he cannot help us to discern the reason for the laws or the inward nature of the forces on which they depend. He can tell us the “that” but not the “why”; he cannot show us in a single case that the effect follows necessarily a priori from the nature of the cause, that any other effect than the one which actually takes place would be logically impossible. He has studied the law of gravitation, but this law does not enable him to see why material bodies should attract each other in this fashion; it is only a generalized statement of the fact that they do. He knows that certain substances, if absorbed by eating, will nourish and others destroy our tissues; but he cannot say why they should do so. He can no doubt analyse them further and discover that, for example, meat is nourishing because it contains a large proportion of nitrogenous matter, but he could not tell a priori whether this nitrogenous matter would be likely to nourish or to poison us. Only where mathematics can be applied do we see necessity in such a way that any alternative becomes inconceivable to us; but mathematics alone can never establish from a quantity present here and now what quantity there will be at a later time or in another part of space. Mathematics can show, e.g., that, if there is 2 + 2 here and now, there must be 4 here and now, not that, if there is 2 + 2 here and now, there will be 4 in an hour's time or a mile away; and therefore it cannot be made the sole basis of any causal law whatever.

THE question which I am to raise for discussion is one which has long been debated by philosophers, and consequently I consider it doubtful whether anything very new can be said on the matter. But it may be profitable to review once more the present position of the controversy and to have in mind the reasons which at present make the question of interest and of importance.

The metaphysical doctrine of the Stoics is a remarkable instance of a theory that appears to be materialism, but is in truth a form of unconscious ideal-realism. It is worth while to give an exposition of it in order to show that this is really the case, and, incidentally, to explain why a materialistic philosophy seems so attractive to many minds. I will refer chiefly to the teaching of the ancient Stoics, i.e. of Zeno, Cleanthes, and Chrysippus, and also to the later doctrine of Posidonius.

There is so much truth in the conception of the state as a natural organism and of man as a political animal, as commonly contrasted with the various theories of the state as an artificial formation based on contract, or implied contract, that Aristotle's proposition is rarely criticized from any other standpoint. When Aristotle said that man was a political animal, that is that political life was his nature, and consequently that the state, as the ultimate development of his nature, was a natural institution, or, as we should say, an organism, he was, we may say with a good deal of certainty, speaking in the light of this contrast. But his theory must be judged on its own merits, and not on the demerits of that which he was attacking. We may grant that the state is natural; but we may nevertheless mean by “natural” something other than Aristotle means. And if our conception of Nature is different from his, it will follow that our agreement about the state is one of words only.

Some of the time we are conscious. But we are a very small part of the universe, and consciousness, so it seems, is a very small part of us. Yet that very small part is the starting-point of all knowledge and the field in which all our experience occurs.

I noted two directions in which the scientific worker is seeking to advance. He is trying to give a more complete account of the actual detail of what is happening, and he is seeking wider and wider generalizations. As an observer, he must note what he observes, and, it would seem, omit nothing. But in seeking generalizations he must select, from among the features he observes, only those which he takes to be of general significance. Thence arises at least the appearance of a conflict in his activities. If he is too intent on the details of what he observes, his generalizations suffer; but if he leaves aside details too readily, his generalizations suffer equally. There is danger both in omitting and in not omitting.

Had I been asked any time last century to discourse to philosophers on a subject entitled “Beyond Physics,” I should have taken it as meaning “Metaphysics,” and have declined on the ground that they knew more about it than I did. But now that the subject has been suggested to me in the second quarter of the twentieth century, I realize that a certain number of physicists, especially mathematical ones, have gone beyond themselves in a semiphilosophical direction, have thrown our old physical ideas into some confusion, and have devised a number of complicated abstractions which they seem able to deal with by recondite methods invented for other purposes by the pure mathematicians. Of these they do not attempt to form any mental image, and do not encourage us to try to do so. They mistrust the method of physical imagery, or what they call “models,” which constituted one of the main methods of investigation in the nineteenth century; they are content to deal with abstract symbols, which presumably represent something real, though they mistrust the term “reality,” and decline to define it. The younger modern physicists are content to work in a nebulous region of unknown and perhaps unknowable entities, remote from our ordinary conceptions and everyday experiences; so that, whereas the old idea of explanation consisted in trying to express mysterious or recondite phenomena in terms of something with which we were more familiar, they now point out that our apparent familiarity with those simpler things was more or less of an illusion, that they furnished no valid explanation at all, and that the physical and engineering conceptions or habits of thought on which we depended were largely misleading.