Esti de to gignomenon toionde. katakomizontes hoi par' hêmin geôrgoi tous || ek tôn agrôn pyrous eis tên polin 56 en hamaxais tisin, hotan hyphelesthai boulêthôsin, hôste mê phôrathênai, kerami' atta plêrôsantes hydatos mesois autois enistasin. helkontes oun ekeinoi dia tou keramiou to hygron eis hautous onkon men kai baros prosktôntai, katadêloi d' ou pany gignontai tois horôsin, ei mê tis propepysmenos êdê periergoteron episkopoito. kaitoi g' ei boulêtheiês en hêliô katatheinai pany thermô tauton angeion, elachiston pantelôs heurêseis to dapanômenon eph' hekastês hêmeras. houtôs ara kai tês hêliakês thermasias tês sphodras ischyroteran hoi pyroi dynamin echousin helkein eis heautous tên plêsiazousan hygrotêta. lêros oun entautha makros hê pros to leptomeres phora tou periechontos hêmas aeros kai malisth' hotan hikanôs ê thermos, poly men hyparchontos ê kata tous pyrous leptomeresterou, dechomenou d' oude to dekaton meros tês eis ekeinous metalambanomenês hygrotêtos. XV Since then, we have talked sufficient nonsense--not willingly, but because we were forced, as the proverb says, "to behave madly among madmen"--let us return again to the subject of urinary secretion. Here let us forget the absurdities of Asclepiades, and, in company with those who are persuaded that the urine does pass through the kidneys, let us consider what is the character of this function. For, most assuredly, either the urine is conveyed by its own motion to the kidneys, considering this the better course (as do we when we go off to market![134]), or, if this be impossible, then some other reason for its conveyance must be found. What, then, is this? If we are not going to grant the kidneys a faculty for attracting this particular quality,[135] as Hippocrates held, we shall discover no other reason. For, surely everyone sees that either the kidneys must attract the urine, or the veins must propel it--if, that is, it does not move of itself. But if the veins did exert a propulsive action when they contract, they would squeeze out into the kidneys not merely the urine, but along with it the whole of the blood which they contain.[136] And if this is impossible, as we shall show, the remaining explanation is that the kidneys do exert traction.