Page:1888 Cicero's Tusculan Disputations.djvu/270

264 and equable motion. And as long as this motion remains in us, so long does sense and life remain; but the moment that it abates and is extinguished, we ourselves decay and perish.

By arguments like these, Cleanthes shows how great is the power of heat in all bodies. He observes that there is no food so gross as not to be digested in a night and a day; and that even in the excrementitious parts, which nature rejects, there remains heat. The veins and arteries seem, by their continual quivering, to resemble the agitation of fire; and it has often been observed when the heart of an animal is just plucked from the body that it palpitates with such visible motion as to resemble the rapidity of fire. Everything, therefore, that has life, whether it be animal or vegetable, owes that life to the heat inherent in it; it is this nature of heat which contains in itself the vital power which extends throughout the whole world. This will appear more clearly on a more close explanation of this fiery quality, which pervades all things.

Every division, then, of the world (and I shall touch upon the most considerable) is sustained by heat; and first it may be observed in earthly substances that fire is produced from stones by striking or rubbing one against another; that "the warm earth smokes" when just turned up, and that water is drawn warm from well-springs; and this is most especially the case in the winter season, because there is a great quantity of heat contained in the caverns of the earth; and this becomes more dense in the winter, and on that account confines more closely the innate heat which is discoverable in the earth.

X. It would require a long dissertation, and many reasons would require to be adduced, to show that all the seeds which the earth conceives, and all those which it contains having been generated from itself, and fixed in roots and trunks, derive all their origin and increase from the temperature and regulation of heat. And that even every liquor has a mixture of heat in it is plainly demonstrated by the effusion of water; for it would not congeal by cold, nor become solid, as ice or snow, and return again