A few articles (such as "Misconceptions about Medieval Medicine: Humors, Leeches, Charms, and Prayers") state that Hippocrates observed that blood, when removed from the body, would separate into four layers, and that this stratification partially inspired his humoral theory. What passages from antiquity describe this observation? Is it mentioned anywhere in the Hippocratic corpus? If so, where?

1 Answer 1


This thesis appeared in the "The Humans nature" book. Ancients thought it was the work of Hippocrates, but sooner it was the work of his son-in-law Polibius.

It is got from STORIA DELLA FILOSOFIA (REALE - ANTISERI), the first volume.

Oh, wiki says this, too. http://en.wikipedia.org/wiki/On_the_Nature_of_Man (On the Nature of Man is a work in the Hippocratic Corpus.)

What about observations, it is not strange to me, that very few articles mention observations conducted by Hyppocrates. In the Antic world the knowledge had to be pure, not tainted by the low reality. It had to go from inside. Remember Aristoteles, that thought that flies have 4 legs and never tried to recount. So, even if Hippocrates did measured something (he could, for medicine couldn't be without practice), he would never write about it somewhere. IMHO, the articles mentioned fall into the vice of anachronism. They give post-Bacon philosophy to the scientists of the pre-Bacon times.

Even if there will be found some later work that would mention such observations of Hippocrates, it would be mostly probable, that some later scientist simply covered so his own observations by the authority of Hippocrates - very usual practice in the Middle Ages.

  • "On the Nature of Man" discusses the humoral theory, but I don't see it describe the observation that drained blood stratifies. The closest I can find in it is "And when men are cut, the blood that flows is at first very hot and very red, and then it flows with more phlegm and bile mixed with it," which is in a section describing how all fluid, when forced from the body, eventually consist of a mixture of humors, in support of the thesis that human nature consists of a mixture of humors rather than a single element.
    – outis
    Feb 4, 2012 at 22:20
  • look the edited answer
    – Gangnus
    Feb 6, 2012 at 9:04
  • RE: attitude toward observation-not so. From Galen's commentary on the very work: "Of matters in dispute based on skill, observation decides some, and reasoning decides others. Things decided by observation, therefore, require a finely discerning observation, and those decided by reasoning require a well-trained argumentation. [...] To know whether ruminants have four stomachs and sheep have one, observation is required, not reasoning."
    – outis
    Feb 6, 2012 at 11:21
  • Oh, hat off to Galen. And my great thanks and +1 to you. I didn't know he spoke about observations before Bacon. But Hippocrate lived about 5 centuries earlier. And I am not sure there were others "admittedly observers" except Galen in these times. Galen could invent that observations of Hippocrate to protect his own thoughts.
    – Gangnus
    Feb 6, 2012 at 11:30
  • Simplicius ascribed the imperative to "account for appearances" (σωζειν τα φαινομενα; the notion that a theory must account for observations) to the Platonic school in his comments (written somewhere between 529-560 AD) on Aristotle's "On the Heavens". That's not to say that the Platonic school argued that truth can arise from perceptions, but it points out that observation has a place. Epicurus (341-270 BC), on the other hand, did argue that truth can be determined by knowledge gained from the senses.
    – outis
    Feb 6, 2012 at 12:10

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