For the popularisation of science, which was to be one of the features of the nineteenth century, was in fact a condition of the success of the idea of Progress.  That idea could not insinuate itself into the public mind and become a living force in civilised societies until the meaning and value of science had been generally grasped, and the results of scientific discovery had been more or less diffused.  The achievements of physical science did more than anything else to convert the imaginations of men to the general doctrine of Progress.

Before the later part of the seventeenth century, the remarkable physical discoveries of recent date had hardly escaped beyond academic circles.  But an interest in these subjects began to become the fashion in the later years of Louis XIV.  Science was talked in the salons; ladies studied mechanics and anatomy.  Moliere’s play, Les Femmes savantes, which appeared in 1672, is one of the first indications.  In 1686 Fontenelle published his Conversations on the Plurality of Worlds, in which a savant explains the new astronomy to a lady in the park of a country house. [Footnote:  The Marquise of the Plurality of Worlds is supposed to be Madame de la Mesangere, who lived near Rouen, Fontenelle’s birthplace.  He was a friend and a frequent visitor at her chateau.  See Maigron, Fontenelle, p. 42.  The English translation of 1688 was by Glanvill.  A new translation was published at Dublin as late as 1761.] It is the first book—­at least the first that has any claim to be remembered—­in the literature of popular science, and it is one of the most striking.  It met with the success which it deserved.  It was reprinted again and again, and it was almost immediately translated into English.

The significance of the Plurality of Worlds is indeed much greater than that of a pioneer work in popularisation and a model in the art of making technical subjects interesting.  We must remember that at this time the belief that the sun revolves round the earth still prevailed.  Only the few knew better.  The cosmic revolution which is associated with the names of Copernicus, Kepler, and Galileo was slow in producing its effects.  It was rejected by Bacon; and the condemnation of Galileo by the Church made Descartes, who dreaded nothing so much as a collision with the ecclesiastical authorities unwilling to insist on it. [Footnote:  Cp.  Bouillier, Histoire de la philosophie cartesienne, i. p. 42-3.] Milton’s Raphael, in the Eighth Book of Paradise Lost (published 1667), does not venture to affirm the Copernican system; he explains it sympathetically, but leaves the question open. [Footnote:  Masson (Milton’s Poetical Works, vol. 2) observes that Milton’s life (1608-74) “coincides with the period of the struggle between the two systems” (p. 90).  Milton’s friends, the Smectymnians, in answer to Bishop Hall’s Humble Remonstrance (1641), “had cited the Copernican doctrine as an unquestionable instance of a supreme absurdity.”  Masson has some apposite remarks on the influence of the Ptolemaic system “upon the thinkings and imaginations of mankind everywhere on all subjects whatsoever till about two hundred years ago.”] Fontenelle’s book was an event.  It disclosed to the general public a new picture of the universe, to which men would have to accustom their imaginations.