said St. Augustine after Lactantius, "that, if there were men
under our feet, their heads would point downward, and that they
would fall into the sky?" The bishop of Hippo, who thought the
earth flat because it appeared so to the eye, supposed in
consequence that, if we should connect by straight lines the
zenith with the nadir in different places, these lines would be
parallel with each other; and in the direction of these lines he
traced every movement from above to below. Thence he naturally
concluded that the stars were rolling torches set in the vault of
the sky; that, if left to themselves, they would fall to the
earth in a shower of fire; that the earth was one vast plain,
forming the lower portion of the world, &c. If he had been asked
by what the world itself was sustained, he would have answered
that he did not know, but that to God nothing is impossible.
Such were the ideas of St. Augustine in regard to space and
movement, ideas fixed within him by a prejudice derived from an
appearance, and which had become with him a general and
categorical rule of judgment. Of the reason why bodies fall his
mind knew nothing; he could only say that a body falls because it
falls.

With us the idea of a fall is more complex: to the general ideas
of space and movement which it implies, we add that of attraction
or direction towards a centre, which gives us the higher idea of
cause. But if physics has fully corrected our judgment 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