First Complete Latin Philo

...of the most perfect [number], one may not falsely call it the cause and source. For what the decad is in actuality, the quaternary seems to be in potentiality. If, therefore, the numbers are added in succession from the unit up to the quaternary, they produce the decad: which is the limit of the infinity of numbers, toward which, as if to a goal, they revolve and reflect back upon themselves. Moreover, the same quaternary contains the musical ratios of the harmonies, namely the fourth, the fifth, the octave, and the double octave, from which the most perfect concord is produced. For the fourth has a sesquitertial proportion; the fifth, a sesquialteran; the octave, a double proportion. The quaternary contains all these proportions within itself: the sesquitertial in four to three; the sesquialteran in three to two; the double in two to one, or four to two; and the quadruple in four to one.

There is also another power of the quaternary, wondrous to speak of and to contemplate. For this first reveals the nature of a solid, whereas the preceding numbers are dedicated to incorporeal things. For in the unit is reckoned the point, as the geometers call it; in the dyad, the line. This is length without breadth; where breadth is added, it becomes a surface, pertaining to the triad. This, so that it might become a body solid by nature, lacks only depth; when this is joined to the triad, it becomes the quaternary. Hence much esteem has fallen to this number, which has led us from an incorporeal and intelligible essence to the consideration of a body extending in three dimensions, which by its own nature is the first thing perceived by the senses. He who understands this little will learn it from a common game. Those who play with nuts are accustomed, having first placed three on a plane, to superimpose a fourth upon them in the form of a pyramid. That triangle on the plane, therefore, consists within the triad; when a fourth is superimposed, it makes a quaternary in number, but in figure a pyramid, which is now a solid body.

Furthermore, it must not be ignored that four is the first of the numbers to be a square and evenly-even, a measure of equality and justice; and that it alone of these consists of both composition and innate power. By composition, from two and two; again, by power, from twice two, displaying a certain most beautiful form of harmony which is present in none of the other numbers. For presently the senary, composed of two triads, is no longer produced by these multiplied by themselves, but another, namely the novenary. The quaternary is also endowed with many other powers, which must be pointed out more accurately and copiously in its own treatise. For now it will suffice to have added this: that it gave the beginning to the generation of the whole heaven and the world. For the four elements from which this universe was fashioned flowed from the number four as if from a fountain; and likewise these four seasons by which the year is distinguished, from which living creatures and plants come forth, namely winter, spring, summer, and autumn.

Since, therefore, the aforementioned number has been honored by nature with so many privileges, the Creator of things necessarily adorned the heaven on the fourth day, employing the most beautiful and most divine ornaments, that is, the light-bearing stars; and knowing that light is the most excellent of all things, He made it the instrument of sight, the most excellent of the senses. For what the mind is in the soul, that the eye is in the body. For each sees: the one, intelligible things; the other, sensible things. Now the use of the mind...