The fallacious axis upon which humanity believed itself to revolve has suddenly snapped in two; and the huge platform which carries mankind, after swaying for some time in our alarmed imaginations, has quietly settled itself again to turning on the real pivot that had always supported it. Nothing is changed except one of those unexplained phrases with which we cover the things which we do not understand. Hitherto, the pivot of the world seemed to us to be made up of spiritual forces; to-day, we are convinced that it is composed of purely material energies. We flatter ourselves that a great revolution has been accomplished in the kingdom of truth. As a matter of fact, there has been, in the republic of our ignorance, but a permutation of epithets, a sort of verbal _coup d'État_, the words "mind" and "matter" being no more than the interchangeable attributes of the same unknown. III But if it be true that, in themselves, these epithets should have merely a literary value, since both are probably inaccurate and no more represent reality than the epithet "Atlantic" or "Pacific" represents the ocean to which it is applied, they do, nevertheless, according as we adhere exclusively to the first or to the second, exercise a prodigious influence over our future, over our morality and, consequently, over our happiness. We wander round the truth, with no other guide than hypotheses which light, by way of torches, some famous, but magic phrases, and soon those phrases become for us so many living entities, which place themselves at the head of our physical, intellectual and moral activity. If we believe that mind directs the universe, all our researches and all our hopes are concentrated upon our own mind, or rather upon its verbal and imaginative faculties and we become addicted to theology and metaphysics. If we are persuaded that the last word of the riddle lies in matter, we apply ourselves exclusively to interrogating this and we place our confidence in experimental science only. We are beginning, however, to recognize that "materialism" and "spiritualism" are merely the two opposite, but identical names of our impotent labour after comprehension. Nevertheless, each of the two methods drags us into a moral world that seems to belong to a different planet. IV Let us pass over the accessory consequences. The great advantage of the spiritualistic interpretation is that it gives to our life a morality, an aim and a meaning that are imaginary, but very much superior to those which our cultivated instincts proffer to it. The more or less unbelieving spiritualism of to-day still draws light from the reflection of that advantage and preserves a deep, though somewhat shapeless faith in the final supremacy and the indeterminate triumph of the mind.