XX. (62) Then when earth and heaven had been adorned with their befitting ornaments, one with a triad, and the other, as has been already said, with a quaternion, God proceeded to create the races of mortal creatures, making the beginning with the aquatic animals on the fifth day, thinking that there was no one thing so akin to another as the number five as to animals; for animate things differ from inanimate in nothing more than in sensation, and sensation is divided according to a fivefold division, into sight, hearing, taste, smell, and touch. Accordingly, the Creator allotted to each of the senses its appropriate matter, and also its peculiar faculty of judgment, by which it should decide on what came before it. So sight judges of colours, and hearing of sounds, and taste of juices, and smell of vapours, and touch of softness and hardness, and of heat and cold, and of smoothness and roughness: (63) therefore He commanded all the races of fish and sea-monsters to stand together in their places, animals differing both in their sizes and in their qualities; for they vary in different seas, though in some cases they are the same, and every animal was not formed to live every where. And was not this reasonable? For some of them delight in marshy places, and in water which is very deep; and some in sewers and harbours, being neither able to crawl up upon the land, nor to swim off far from the land. Some, again, dwell in the middle and in the deep sea, and avoid all the projecting promontories and islands and rocks: some also exult in fine weather and in calm, and some in storms and heavy surf. For being exercised by continual buffetings, and being in the habit of withstanding the current by force, they are very vigorous and become stout. After that he created the races of birds as akin to the races of aquatic animals (for they are each of them swimmers), leaving no species of creatures which traverse the air unfinished.