[119] but now, as things are, the constant inequalities which exist, and the vast heights of many mountains, reaching up even to the sky, are so many proofs that the earth is not eternal. For otherwise, as I have said before, all the earth would long since have been rendered level from one extremity to the other by the vast rains which would have fallen from the eternal commencement of time; for it is the character of the nature of water, and especially of such as descends in a heavy fall from lofty places, to push some things away by force, and to cut out and hollow other places by its continual dropping, and in this manner to operate on the hard, rugged, stony ground not less than men digging.