(14) Why did the rain of the deluge last forty days and an equal number of nights? (#Ge 7:4). In the first place, the word day is used in a double sense. The one meaning that time which is from morning to evening, that is to say, from the first rising of the sun in the east to his sinking in the west. Therefore they who make definitions, say, “That is day, as long as the sun shines on the earth.” In another sense, the word day is used of the day and night together. And in this sense we say that a month consists of thirty days, combining together and computing the period of night in the same calculation. These premises having been first laid down thus, I say that the word now spoken of has not been incorrectly employed, inasmuch as it implies forty days and forty nights; but is also so used in order to suggest a double number determined for the generation of mankind, namely, forty and eighty, as many men skilled in medicine, and indeed also in physical science, have suggested; but it is especially described in the sacred law, which was to them also the first principle of natural science. Since therefore destruction was on the point of overwhelming all men and women every where on account of the excessive combination of iniquities and quarrels, the Judge of all considered it becoming to allot an equal time to their destruction to that which he had consumed in the original creation of nature and to the work of giving life to the world; for the principle of procreation is the perseverance of seed in the different parts; but it was necessary to honour the male creature with pure light, which knows not the shade; but the woman had a mixture in her body of night and darkness. Therefore, in the creation of the whole world, the excess of the male or the unequal number, being composed of unity, becomes the parent of square numbers; but the woman who is an unequal number, being compounded of duality, becomes the parent of other long numbers. Moreover, the square is splendour and light combining together by the equality of the sides; but the other numbers being long necessarily exhibit night and darkness by reason of their inequality, since that which is in excess throws a shade over that which lies beneath the excess. In the second place, the number forty is the produce of many virtues, as has been suggested in another place. It is also often used for the judgment of legislation, both with reference to those persons who have done any thing rightly deserving of praise and honour, and also with reference to those who on account of their sins meet with reproaches and punishments; so that it is superfluous to adduce proofs to demonstrate what is evident.