 In the early modern period, William Harvey adopted an Aristotelian stance in the context of both physiology and development (Lennox 2006). The relation between parts and wholes in ontogeny, including relevant material properties, is constantly in view (Harvey 1981 [1651]). Although Harvey used “mechanistic” analogies, referring to the motion of the heart in terms of interlocking gears or to the heart itself as a pump (Distelzweig 2016),  René Descartes  famously disputed Harvey’s claims from the perspective of the  “mechanical philosophy”.  Descartes sought to explain the movement of the heart not in terms of function but rather by appeal only to the matter in motion composing the circulating blood that is heated and thus expands akin to fermentation (Description of the Human Body). He also attempted to explain embryology in terms of matter and motion alone; e.g., tissue and organ origination is accounted for via matter slowing down and aggregating in different regions of the embryo (Des Chene 2001, ch. 2; Smith 2006, Part II).  Robert Boyle  defended teleological explanations in anatomy and physiology (specifically, the integrated relations among the parts and whole of an organism) by laying out how they were compatible with and supported by mechanistic explanations (Lennox 1983). Thus, he offered a version of epistemic reduction in line with his conception of mechanical philosophy, which included a heterogeneous methodology (reductionist and non-reductionist) and concomitant reservations about ontological reduction.  Baruch Spinoza  famously used the image of a worm in a bloodstream to engage the theme of part-whole relations and their complexity in a 1665 letter to Henry  Oldenburg.[3]