"The blood, too, acts in like manner above the powers of the elements, because, when it has come into existence as the first generated part and the innate heat, as is brought to pass in the semen and spirits, the blood constructs the remaining parts of the whole body in order; and does so with the highest foresight and understanding,[442] acting to a certain end and as though by some use of reason.[443] Surely the blood does not accomplish these things because it is composed of elements and draws its origin from fire, but because by the grace of plastic power and vegetative soul it is made the first generated heat and the immediate and fitting instrument of life."[444] CHAPTER XII THE CIRCULATION OF THE BLOOD AND THE CIRCULATION OF THE HEAVENS The discoverer of the circulation would have been no fit pupil of Aristotle if he had limited his ken to the microcosm; nor were such limitations common in an age when astrology was not so far out of countenance as now. We have found Harvey discussing "the element of the stars" and reverently affirming the dependence of all life upon the sun as well as upon its Creator. We have found him also, in dealing with the powers of the blood, affirming that "lower and corruptible things are subject to other higher and incorruptible things," and in that connection paraphrasing a passage in which Aristotle deals with "the Cosmos which is about the earth." Of this--that is, of the sum of things between our globe and the moon's sphere--the ancient philosopher says:-- "Of necessity it is conjoined, in a way, with the courses on high, so that its entire power is governed thence; for that which originates motion in everything must be recognized as first cause."[445] In "the courses on high" the divine living existences of heaven circulated forever, ruling the lower Cosmos as cycle succeeded cycle in endless series and the seasons endlessly recurred. In a few pregnant words Aristotle had dealt with the results of this Cosmic circulation, as follows:-- "There is said to be a circle in the affairs both of mankind and of whatever else is possessed of natural motion and is subject to generation and corruption."[446]