He goes on to observe that antiquity is enlarged and exalted by distance:  “In our own day we esteemed our ancestors more than they deserved, and now our posterity esteems us more than we deserve.  There is really no difference between our ancestors, ourselves, and our posterity.  C’est toujours la meme chose.”  But, objects Montaigne, I should have thought that things were always changing; that different ages had their different characters.  Are there not ages of learning and ages of ignorance, rude ages and polite?  True, replies Socrates, but these are only externalities.  The heart of man does not change with the fashions of his life.  The order of Nature remains constant (l’ordre general de la Nature a l’air bien constant).

This conclusion harmonises with the general spirit of the Dialogues.  The permanence of the forces of Nature is asserted, but for the purpose of dismissing the whole controversy as rather futile.  Elsewhere modern discoveries, like the circulation of the blood and the motions of the earth, are criticised as useless; adding nothing to the happiness and pleasures of mankind.  Men acquired, at an early period, a certain amount of useful knowledge, to which they have added nothing; since then they have been slowly discovering things that are unnecessary.  Nature has not been so unjust as to allow one age to enjoy more pleasures than another.  And what is the value of civilisation?  It moulds our words, and embarrasses our actions; it does not affect our feelings. [Footnote:  See the dialogues of Harvey with Erasistratus (a Greek physician of the third century B.C.); Galileo with Apicius; Montezuma with Fernando Cortez.]

One might hardly have expected the author of these Dialogues to come forward a few years later as a champion of the Moderns, even though, in the dedicatory epistle to Lucian, he compared France to Greece.  But he was seriously interested in the debated question, as an intellectual problem, and in January 1688 he published his Digression on the Ancients and Moderns, a short pamphlet, but weightier and more suggestive than the large work of his friend Perrault, which began to appear nine months later.

3.

The question of pre-eminence between the Ancients and Moderns is reducible to another.  Were trees in ancient times greater than to-day?  If they were, then Homer, Plato, and Demosthenes cannot be equalled in modern times; if they were not, they can.

Fontenelle states the problem in this succinct way at the beginning of the Digression.  The permanence of the forces of Nature had been asserted by Saint Sorlin and Perrault; they had offered no proof, and had used the principle rather incidentally and by way of illustration.  But the whole inquiry hinged on it.  If it can be shown that man has not degenerated, the cause of the Moderns is practically won.  The issue of the controversy must be decided not by rhetoric but by physics.  And Fontenelle offers what he regards as a formal Cartesian proof of the permanence of natural forces.