How many types of matter for a mechanical philosophy?

Aristotle’s notion of prime matter became one of the main targets of the early modern novatores. It was decried as a ridiculous entity that was at once pure potentiality and yet capable of giving body to substantial forms. These substantial forms, in turn, constituted the second main target of derision as their ontological status seemed equally ill-defined. This double attack can be traced through such novatores as Patrizzi, Bruno, Basson, Gorlaeus and Descartes all the way up to Boyle. One of the principal alternatives that was developed in the early modern period tried to combine matter and form differently, by attributing shapes – that is, figurae instead of formae – to chunks of universal matter. This is the model that we usually associate with the intellectual program of the mechanical philosophy. The ontologically most radical of these models – Descartes’ – attempted to explain all physical and chemical properties and processes exclusively on the basis of one universal matter, which was distinguished by a limited number of geometrically defined sub-types. But this ontological scarcity had some serious explanatory drawbacks. As a matter of fact, there existed in the seventeenth-century two chief alternatives. One was a type of atomism that retained substantial forms at the fundamental level of the atom. This is a model that is usually associated with Daniel Sennert and his followers. The second was a two-tier model, with atoms defined in terms of a universal matter, and upper levels (molecules, for example), characterized by substantial forms, semina, or vital forces. This second solution is found in a more or less worked-out models in Beeckman, Basson, Gassendi or Charleton. This lecture will try to analyze this general situation and situate these three methods of replacing Aristotle’s conception of matter and form, also from the point of view of eighteenth-century developments in the conception of matter.