On The Holy Trinity by St. Augustine
Chapter 11.--Number, Weight, Measure.
18. But because those things which are impressed on the memory singly, can be conceived according to number, measure seems to belong to the memory, but number to the vision; because, although the multiplicity of such visions is innumerable, yet a limit not to be transgressed is prescribed for each in the memory. Therefore, measure appears in the memory, number in the vision of things: as there is some measure in visible bodies themselves, to which measure the sense of those who see is most numerously adjusted, and from one visible object is formed the vision of many beholders, so that even a single person sees commonly a single thing under a double appearance, on account of the number of his two eyes, as we have laid down above. Therefore there is some measure in those things whence visions are copied, but in the visions themselves there is number. But the will which unites and regulates these things, and combines them into a certain unity, and does not quietly rest its desire of [sensuously] perceiving or of conceiving, except in those things from whence the visions are formed, resembles weight. And therefore I would just notice by way of anticipation these three things, measure, number, weight, which are to be perceived in all other things also. In the meantime, I have now shown as much as I can, and to whom I can, that the will is the uniter of the visible thing and of the vision; as it were, of parent and of offspring; whether in [sensuous] perception or in conception, and that it cannot be called either parent or offspring. Wherefore time admonishes us to seek for this same trinity in the inner man, and to strive to pass inwards from that animal and carnal and (as he is called) outward man, of whom I have so long spoken. And here we hope to be able to find an image of God according to the Trinity, He Himself helping our efforts, who as things themselves show, and as Holy Scripture also witnesses, has regulated all things in measure, and number, and weight.