Have you ever plunged into the immensity of space and time by reading the geological treatises of Cuvier? Borne away on the wings of his genius, have you hovered over the illimitable abyss of the past as if a magician's hand were holding you aloft? As one penetrates from seam to seam, from stratum to stratum and discovers, under the quarries of Montmartre or in the schists of the Urals, those animals whose fossilized remains belong to antediluvian civilizations, the mind is startled to catch a vista of the milliards of years and the millions of peoples which the feeble memory of man and an indestructible divine tradition have forgotten and whose ashes heaped on the surface of our globe, form the two feet of earth which furnish us with bread and flowers. Is not Cuvier the greatest poet of our century? Certainly Lord Byron has expressed in words some aspects of spiritual turmoil; but our immortal natural historian has reconstructed worlds from bleached bones.

If you wish to learn from the theoretical physicist anything about the methods which he uses, I would give you the following piece of advice: Don't listen to his words, examine his achievements. For to the discoverer in that field, the constructions of his imagination appear so necessary and so natural that he is apt to treat them not as the creations of his thoughts but as given realities.