First Complete Latin Philo

...and the elder, then into the dyad and the pentad, and lastly into the triad and the tetrad. This proportion of numbers is also exceedingly musical; for six to one have a sixfold ratio. Now, the sixfold ratio produces the greatest interval between tones, by which the lowest is distant from the highest, as we shall demonstrate when we have transferred our discourse from numbers to harmonies. Furthermore, five to two show the greatest power in harmony, being nearly equivalent to the harmony of the diapason, as appears most clearly in the rules of that art. Moreover, four to three produce the first harmony, the sesquitertian, which is the diatessaron. Besides this, the septenary brings forth another beauty of its own, and one of sacred consideration. For since it consists of the triad and the tetrad, it naturally exhibits a figure that is upright in things and never inclining. How this happens must be declared. The rectangular form, since it is the principle of qualities, consists of these numbers: 3, 4, and 5. But three and four, which are indeed the essence of the septenary, produce a right angle; for the obtuse and the acute display inequality, confusion, and disparity, since they are sharper or blunter than is right. But the right angle admits of no comparison, nor does it become "righter" than another right angle; it is always like itself, and never varies its own nature. Now if the right-angled triangle is the principle of figures and qualities, and if in this the triad and the tetrad together—the essence of the septenary—provide that most necessary thing, the right angle, then this number should deservedly be considered the source of every figure and every quality. To this is added also that 3 is the number of the plane figure, since after the unit is the point, the line is arranged according to the dyad, and the surface according to the triad. Furthermore, the tetrad pertains to the solid body, as height is added to the surface by the addition of a unit. From this it is clear that the essence of the septenary is the principle of geometry and of measuring solids, and to speak briefly, of both incorporeal and corporeal things. So great is the holiness placed in the septenary that it has preeminence over all numbers not exceeding the decad. For among them, some beget and are not begotten; others are begotten but do not beget; others both beget and are begotten. The septenary alone is considered in none of these parts. That this is so must be confirmed by demonstration. One indeed begets all the numbers that follow in order, being itself begotten by none at all. Eight is begotten by twice four, but begets no number among those within the decad. Likewise, four holds the same place between begetters and offspring; for when doubled it begets eight, and it is itself begotten by two doubled. To seven alone, as I said, has nature given neither to beget nor to be begotten. For which reason other philosophers liken this number to the motherless Virgin Victory, whom fables say sprang from the head of Jove; but the Pythagoreans liken it to the ruler of this universe. For whatever neither begets nor is begotten remains unmoved. For generation is in motion, since that which is begotten is not without motion. For the one moves to beget, the other to be begotten. But that ancient prince and author alone neither moves nor is moved, whose image the septenary may deservedly be called. Philolaus bears witness to my words in these terms:

There is, he says, a God, the author and prince of all things, always one, stable, immovable, like unto himself, unlike others.

Therefore, in intelligible things, the septenary appears immovable and impassible...