In France we trace this law through a succession of master minds,--first of whom in time, as in authority, is Descartes, the chief of French philosophy. His life was crowded with triumphs of intellect, and after death his spirit seemed for a time to rule all departments of study. Like the universal soul of the Stoics, it was everywhere. Though not formally enunciating the Law of Progress, his "Discourse on Method," first published in 1637, acknowledged its influence in natural science. "The experience which I have in physics," he says, "teaches me that it is possible to arrive at a knowledge of many things which will be very useful to life, and that we may yet discover methods by which man, comprehending the force and the action of fire, water, air, stars, skies, and all the other bodies which environ us, as distinctly as we comprehend the different trades of our artisans, shall be able to employ them in the same fashion for all the uses to which they are appropriate, and thus shall render himself master and possessor of Nature." In these new triumphs of knowledge, he says, "men may learn to enjoy the fruits of the earth without trouble; their health will be preserved, and they will be able to exempt themselves from an infinitude of ills, as well of body as of mind, and even, perhaps, from the weakness of old age." As I repeat these words, uttered long before the steam-engine, the railroad, the electric telegraph, and the use of ether, I seem to hear a prophecy, the prophecy of Science, which each day helps to fulfil. "Without intending any slight," he continues, "I am sure that even those engaged in these matters will confess that all that they know is almost nothing in comparison with what remains to be known."[250] There is grandeur in the assurance with which the great philosopher announces the Future. [250] Descartes, Discours de la Méthode, Part. 6: OEuvres, Tom. I. pp. 192, 193.