We all know that we dwell in infinity; but this infinity is, for us, only a bare and barren word, a black and uninhabitable void, a formless abstraction, a lifeless expression, to which our imagination can give only a momentary vitality, at the cost of a tiring, solitary, unskilful, unassisted, ungrateful and unfruitful effort. We hold ourselves, in fact, pent in this terrestrial world of ours and in our brief historic ages; and at the most we raise our eyes, from time to time, towards the other planets of our solar system and project our thoughts, which are discouraged from the beginning, as far as the nebulous periods that preceded man’s advent on our globe. More and more deliberately we are directing the whole activity of our intelligence upon ourselves; and, by a regrettable optical illusion, the more it restricts its field of action, the deeper we believe it to be probing. Our thinkers and philosophers, fearing lest they should stray as their predecessors did before them, no longer concern themselves with any but the least disputable aspects, problems and secrets; but, if these are the least disputable, they are also the least sublime; and man, in his quality as a terrestrial animal, becomes the sole object of their investigations. The scientists, on the other hand, are accumulating minor data and observations whose weight is stifling them; yet they no longer dare to thrust them aside or open them out, so as to ventilate them by some general law, some salutary hypothesis, for those which they have hitherto ventured to advance have been pitiably contradicted, one after the other, and scouted by experience. Nevertheless, they are right to act as they do and to continue their investigations according to their narrow and restricted methods; but we are entitled to observe that, the closer they believe that they have drawn to a fugitive truth, the greater are their uncertainty and confusion, the more precarious, imaginary and insufficient seem the foundations upon which they based their confidence and the more fully do they perceive the immense distance that still divides them from the least of life’s secrets. As one of the most illustrious of them, Sir William Grove, prophetically remarked: “The day is fast approaching when it will be confessed that the Forces we know are but the phenomenal manifestations of Realities we know nothing about, but which were known to the Ancients and by them worshipped.” 7 This, indeed, is what we are bound to think if we study slightly this primitive revelation, this ancient wisdom and what has grown out of it. Man once knew more than he now knows. He was ignorant perhaps of the enormous mass of petty details which we have observed and classified and which have enabled us to subdue certain forces which he never thought of turning to account: but it is probable that he understood better than we do their nature, their essence and their origin.