Excerpt: De Natura Deorum

There is, then, an element which holds together and maintains the entire universe, an element, moreover, which is not without sensation and reason. For it is necessary that every element which is not isolated or simple, but which is joined and linked with something else, should have in itself some ruling principle, as, for instance, mind in the case of man, and in the case of animals something similar to mind, which prompts their desires. In trees, and in things which spring from the earth, the ruling principle is supposed to be placed in their roots. By ruling principle I mean the principle which the Greeks call ἡγεμονικόν, which cannot but hold, and which ought to hold, the highest place in each genus. Consequently the thing in which the ruling principle of the whole of nature is contained, must in the same way be the most perfect of all, and the most worthy of power and dominion over all existence. Now we see that in parts of the universe (for there is nothing in the entire universe which is not a part of the whole), sensation and reason exist. These qualities must therefore exist, and exist more vividly and to a greater extent, in that part in which the ruling principle of the universe resides. Consequently the universe must be intelligent, and the element which holds all things in its embrace must excel in perfection of reason; the universe, therefore, must be divine, and so must the element by which the whole strength of theuniverse is held together. This fiery glow which the universe possesses is also far purer, clearer, and nimbler, and on that account better fitted to arouse sensation, than this heat of ours, by which the objects known to us are preserved and made strong. Since, then, men and animals are maintained by this heat, and through it possess motion and sensation, it is absurd to say that the universe is without sensation, when it is maintained by a burning heat which is unmixed, and free, and pure, and at the same time in the highest degree vivid and nimble, especially considering that the heat which belongs to the universe is moved by itself and its own action, and is not stirred by anything distinct from itself, or by impact from outside. For what can be mightier than the universe, so as to act upon and set in motion the heat by which the universe is to be held together?

-Cicero, 'De Natura Deorum.'