A former les esprits comme a former les corps La Nature en tout temps fait les mesmes efforts; Son etre est immuable, et cette force aisee Dont elle produit tout ne s'est point epuisee; ..... De cette mesme main les forces infinies Produisent en tout temps de semblables genies. The "Age of Louis the Great" was a brief declaration of faith. Perrault followed it up by a comprehensive work, his Comparison of the Ancients and the Moderns (Parallele des Anciens et des Modernes), which appeared in four parts during the following years (1688-1696). Art, eloquence, poetry the sciences, and their practical applications are all discussed at length; and the discussion is thrown into the form of conversations between an enthusiastic champion of the modern age, who conducts the debate, and a devotee of antiquity, who finds it difficult not to admit the arguments of his opponent, yet obstinately persists in his own views. Perrault bases his thesis on those general considerations which we have met incidentally in earlier writers, and which were now almost commonplaces among those who paid any attention to the matter. Knowledge advances with time and experience; perfection is not necessarily associated with antiquity; the latest comers have inherited from their predecessors and added new acquisitions of their own. But Perrault has thought out the subject methodically, and he draws conclusions which have only to be extended to amount to a definite theory of the progress of knowledge. A particular difficulty had done much to hinder a general admission of progressive improvement in the past. The proposition that the posterior is better and the late comers have the advantage seemed to be incompatible with an obvious historical fact. We are superior to the men of the dark ages in knowledge and arts. Granted. But will you say that the men of the tenth century were superior to the Greeks and Romans? To this question--on which Tassoni had already touched--Perrault replies: Certainly not. There are breaches of continuity. The sciences and arts are like rivers, which flow for part of their course underground, and then, finding an opening, spring forth as abundant as when they plunged beneath the earth. Long wars, for instance, may force peoples to neglect studies and throw all their vigour into the more urgent needs of self-preservation; a period of ignorance may ensue but with peace and felicity knowledge and inventions will begin again and make further advances. [Footnote: The passages in Perrault's Parallele specially referred to in the text will be found in vol. i. pp. 35-7, 60-61, 67, 231-3.]