William Harvey's theoretical commitment to the primacy of the blood developed from his study of the chick in the hen's egg. Harvey's original contribution, that the blood was the first material embodiment of the soul, is shown to be a crucial departure that enabled him to conceive of the general circulation of the blood.

Defining experiment was particularly vexed in the realm of anatomical dissection and vivisection. Was dissection merely descriptive, or something more? Harvey's discovery of the circulation of the blood and Aselli's discovery of the so-called lacteal veins shaped much anatomical research between the late 1620s and the 1650s. While the techniques of dissection and vivisection gained wide use, there was much debate on the validity of the circulation in particular, and its relationship to the lacteal veins. Critics, particularly the French anatomist (...) Jean Riolan, but also the natural philosopher Pierre Gassendi, focused on the lack of causation in Harvey's method and the lack of medical use and not on his use of vivisection. Jean Pecquet's discovery of the thoracic duct in 1651 changed the terms of the debate by definitively connecting the circulation with the lacteals. Riolan's critiques of Pecquet in the 1650s show profoundly differing notions of the purpose of dissection. While Gassendi eventually accepted Harvey's concept of the circulation, Riolan never did. (shrink)

In this paper I argue that William Harvey believed in a form of astrology. It has long been known that Harvey employed a macrocosm–microcosm analogy and used alchemical terminology in describing how the two types of blood change into one another. This paper then seeks to examine a further aspect of Harvey in relation to the magical tradition. There is an important corollary to this line of thought, however. This is that while Harvey does have a belief in astrology, it (...) is strongly related to Aristotle's views in this area and is quite restricted and attenuated relative to some contemporary beliefs in astrology. This suggests a more general thesis. While Harvey was amenable to ideas which we associate with the natural magic tradition, those ideas had a very broad range of formulation and there was a limit to how far he would accept them. This limit was largely determined by Harvey's adherence to Aristotle's natural philosophy and his Christian beliefs. I argue that this is also the case in relation to Harvey's use of the macrocosm–microcosm analogy and of alchemical terminology, and, as far as we can rely on the evidence, this informs his attitudes towards witches as well. Understanding Harvey's influences and motives here is important in placing him properly in the context of early seventeenth-century thought. (shrink)

Some scholars suspect that thought experiments have something in common with jokes. Moreover, Thomas Kuhn has suggested that what happens to someone who thinks through a thought experiment “is very similar to what happens to a man, like Lavoisier, who must assimilate the result of a new unexpected experimental discovery” (1964: 321). In this paper, I pinpoint the presumed commonalities. I identify, more specifically, what cognitive linguists call “incongruity-resolution” as the problem-solving process not only involved in humor comprehension, but in (...) scientific discovery and thought experimentation as well. (shrink)

The change in the physiological conception of body fluid during the Seventeenth Century exemplifies the beginning of changes in chemical ideas away from humours as irreducible components of fluid systems towards water as the common solvent of an indefinitely large range of solutions. Against the Galenic humoral view of body fluids J.-B. van Helmont postulated ‘latex’, a humour distributed through the body and common to several body fluids. The theory of latex explained experimental findings and provided a basis for Helmont's (...) introduction of diuretics into the treatment of dropsy. Francis Glisson adopted the theory of latex. In this paper it is shown that Helmont contradicted, in part at least, the distinctness of humours by a doctrine of a common reservoir from which various body fluids are drawn. It is further argued that, on the available evidence, Helmont is the originator of this idea of a common reservoir. Through hitherto unremarked and unpublished manuscript evidence, it is shown that Glisson, in adopting the theory of latex, and its therapeutic application, modifies and extends it. In the manuscripts Glisson expresses himself in the language of Helmontian philosophy. Given Glisson's known influence , the question arises what part, if any, is attributable to him in the transmission of the doctrine of the common reservoir. From the point of view of experimental science, that doctrine makes a break with the past no less radical than does, say, that of the circulation. It appears that we have here yet another major contribution of Helmont to the scientific revolution with, through Glisson, a possible channel of transmission of this contribution. (shrink)