in this respect, we still make use of the prejudice of St. Augustine; and when we say that a thing has fallen, we do not mean simply and in general that there has been an effect of gravitation, but specially and in particular that it is towards the earth, and from above to below, that this movement has taken place. Our mind is enlightened in vain; the imagination prevails, and our language remains forever incorrigible. To descend from heaven is as incorrect an expression as to mount to heaven; and yet this expression will live as long as men use language.
All these phrases—from above to below; to descend from heaven; to fall from the clouds, &c.—are henceforth harmless, because we know how to rectify them in practice; but let us deign to consider for a moment how much they have retarded the progress of science. If, indeed, it be a matter of little importance to statistics, mechanics, hydrodynamics, and ballistics, that the true cause of the fall of bodies should be known, and that our ideas of the general movements in space should be exact, it is quite otherwise when we undertake to explain the system of the universe, the cause of tides, the shape of the earth, and its position in the heavens: to understand these things we must leave the circle of appearances. In all ages there have been ingenious mechanicians, excellent architects, skilful artillerymen: any error, into which it was possible for them to fall in regard to the rotundity of the earth and gravitation, in no wise retarded the development of their art; the solidity of their buildings and accuracy of their aim was not affected by it. But sooner or later they were forced to grapple with phenomena, which the supposed parallelism of all perpendiculars erected from the earth’s surface rendered inexplicable: then also commenced a struggle between the prejudices, which for centuries had sufficed in daily practice, and the unpre-
