In this latest century, above all, the experimental _a priori_ method, the only really scientific one, has been put into practice in the natural sciences, and by its aid man has freed himself from the prejudices of the old school of thought, one by one, and from subjective or speculative theories, and confined himself to a careful and intelligent study of the field of observation.
Yes, human science is firmly based and pregnant with possibility, worthy of our homage for its difficult and long-proved past, worthy of our sympathy for its future, big with the promise of useful and profitable discoveries. For nature is henceforth to be a book accessible to the bibliographical researches of the studious, a world open to the investigations of the thinker, a fertile region which the human mind has already visited, and in which we must needs advance boldly, holding in our hand experience as our compass....
An old friend of my terrestrial life recently spoke to me as follows. One of our wanderings had brought us back to the Earth, and we were making a new moral study of this world. My companion remarked that man is to-day familiar with the most abstract laws of mechanics, physics, chemistry, ... that the applications of knowledge to industry are not less remarkable than the deductions of pure science, and that it seems as if the entire universe, wisely studied by man, was to be his royal appanage. As we pursued our journey beyond the bounds of this world, I answered him in the following terms:
"A feeble atom, lost to sight in an imperceptible point of the infinite, man has believed he could embrace in the sweep of his vision the whole expanse of the universe, whereas he can scarcely pass beyond the region he inhabits; he has thought he could study the laws of all nature, and his investigations have scarcely reached the forces in action about him; he has thought he could determine the grandeur of the starry heaven, and he exhausted his powers in the study of a grain of dust. The field of his researches is so small that, once lost to view, the mind seeks in vain to recover it; the human heaven and earth are so small that scarcely has the soul in its flight had time to spread its wings before it has reached the last regions accessible to the observation of man; for the immeasurable Universe surrounds us on all sides, unfolding beyond the limits of our heavens its unknown riches, putting its inconceivable forces into play, and reaching forward into immensity in the splendor of its life.