Chapter 4.—The Ratio of the Single to the Double Comes from the Perfection of the Senary Number. The Perfection of The Senary Number is Commended in the Scriptures. The Year Abounds in The Senary Number.
7. Now this ratio of the single to the double arises, no doubt, from the ternary number, since one added to two makes three; but the whole which these make reaches to the senary, for one and two and three make six. And this number is on that account called perfect, because it is completed in its own parts: for it has these three, sixth, third, and half; nor is there any other part found in it, which we can call an aliquot part. The sixth part of it, then, is one; the third part, two; the half, three. But one and two and three complete the same six. And Holy Scripture commends to us the perfection of this number, especially in this, that God finished His works in six days, and on the sixth day man was made in the image of God. 479 And the Son of God came and was made the Son of man, that He might re-create us after the image of God, in the sixth age of the human race. For that is now the present age, whether a thousand years apiece are assigned to each age, or whether we trace out memorable and remarkable epochs or turning-points of time in the divine Scriptures, so that the first age is to be found from Adam until Noah, and the second thence onwards to Abraham, and then next, after the division of Matthew the evangelist, from Abraham to David, from David to the carrying away to Babylon, and from thence to the travail of the Virgin, 480 which three ages joined to those other two make five. Accordingly, the nativity of the Lord began the sixth, which is now going onwards until the hidden end of time. We recognize also in this senary number a kind of figure of time, in that threefold mode of division, by which we compute one portion of time before the Law; a second, under the Law; a third, under grace. In which last time we have received the sacrament of renewal, that we may be renewed also in the end of time, in every part, by the resurrection of the flesh, and so may be made whole from our entire infirmity, not only of soul, but also of body. And thence that woman is understood to be a type of the church, who was made whole and upright by the Lord, after she had been bowed by infirmity through the binding of Satan. For those words of the Psalm lament such hidden enemies: “They bowed down my soul.” 481 And this woman had her infirmity eighteen years, which is thrice six. And the months of eighteen years are found in number to be the cube of six, viz. six times six times six. Nearly, too, in the same place in the Gospel is that fig tree, which was convicted also by the third year of its miserable barrenness. But intercession was made for it, that it might be let alone that year, that year, that if it bore fruit, well; if otherwise, it should be cut down. 482 For both three years p. 74 belong to the same threefold division, and the months of three years make the square of six, which is six times six.
8. A single year also, if the whole twelve months are taken into account, which are made up of thirty days each (for the month that has been kept from of old is that which the revolution of the moon determines), abounds in the number six. For that which six is, in the first order of numbers, which consists of units up to ten, that sixty is in the second order, which consists of tens up to a hundred. Sixty days, then, are a sixth part of the year. Further, if that which stands as the sixth of the second order is multiplied by the sixth of the first order, then we make six times sixty, i.e. three hundred and sixty days, which are the whole twelve months. But since, as the revolution of the moon determines the month for men, so the year is marked by the revolution of the sun; and five days and a quarter of a day remain, that the sun may fulfill its course and end the year; for four quarters make one day, which must be intercalated in every fourth year, which they call bissextile, that the order of time may not be disturbed: if we consider, also, these five days and a quarter themselves, the number six prevails in them. First, because, as it is usual to compute the whole from a part, we must not call it five days, but rather six, taking the quarter days for one day. Next, because five days themselves are the sixth part of a month; while the quarter of a day contains six hours. For the entire day, i.e. including its night, is twenty-four hours, of which the fourth part, which is a quarter of a day, is found to be six hours. So much in the course of the year does the sixth number prevail.