"If the memory of the past is the instruction of the present and the premonition of the future, it is to be feared that having reached so great excellence, power, wisdom, studies, books, industries will decline, as has happened in the past, and disappear--confusion succeeding to the order and perfection of to-day, rudeness to civilisation, ignorance to knowledge. I already foresee in imagination nations, strange in form, complexion, and costume, overwhelming Europe--like the Goths, Huns, Vandals, Lombards, Saracens of old--destroying our cities and palaces, burning our libraries, devastating all that is beautiful. I foresee in all countries wars, domestic and foreign, factions and heresies which will profane all things human and divine; famines, plagues, and floods; the universe approaching an end, world-wide confusion, and the return of things to their original chaos." [Footnote: It is characteristic of the age that in the last sentence the author goes beyond the issue and contemplates the possibility which still haunted men's minds that the end of the world might not be far off.] But having conducted us to this pessimistic conclusion Le Roy finds it repugnant, and is unwilling to acquiesce in it. Like an embarrassed dramatist he escapes from the knot which he has tied by introducing the deus ex machina. "However much these things proceed according to the fatal law of the world, and have their natural causes, yet events depend principally on Divine Providence which is superior to nature and alone knows the predetermined times of events." That is to say, it depends, after all, on Providence whether the argument from past experience is valid. Who knows whether the modern age may not prove the exception to the law which has hitherto prevailed? Let us act as if it would. This is the practical moral that Le Roy enforces in the last book of his dissertation. We must not allow ourselves to be paralysed or dismayed by the destinies of past civilisations, but must work hard to transmit to posterity all that has been achieved, and augment the discoveries of the past by new researches. For knowledge is inexhaustible. "Let us not be so simple as to believe that the ancients have known and said everything and left nothing to their successors. Or that nature gave them all her favours in order to remain sterile ever after." Here Le Roy lays down Bodin's principle which was to be asserted more urgently in the following century--the permanence of natural forces. Nature is the same now as always, and can produce as great intellects as ever. The elements have the same power, the constellations keep their old order, men are made of the same material. There is nothing to hinder the birth in this age of men equal in brains to Plato, Aristotle, or Hippocrates.