I want to say a little bit about the way Margaret Cavendish thinks about causation. A key aspect of that is an inversion, or set of inversions, of what other modern philosophers were up to. One prominent trend in modern philosophy was what is called mechanism. The central mechanist idea is that many natural phenomena are to be explained as the results of mechanical interactions. The shapes, sizes, and motions of the small parts of things explain, the mechanists argued, more than one might otherwise think. The mechanism of a clock provided a useful example: its apparently non-mechanical ability to tell the time is explained by the shapes, sizes, and motions of the parts inside. The mechanist project, so to speak, was to explain more and more of nature in this sort of way. Descartes provides an obvious example of someone taking this sort of approach. Hobbes provides an even better one, thinking that this sort of mechanical explanation applies to human cognition too.
That Hobbes and Descartes were wrong about things in this general area is one of the themes of the first part of Cavendish’s Philosophical Letters [PL].
One sort of disagreement is with various particular explanatory claims. Here her discussion of Hobbes’s account of perception provides a useful example. Hobbes’s account of sense involves a pressure outside the perceiver, which then leads to a reaction on the inside:
The cause of sense, is the external body, or object, which presseth the organ proper to each sense, either immediately, as in the taste and touch; or mediately, as in seeing, hearing, and smelling: which pressure, by the mediation of the nerves, and other strings, and membranes of the body, continued inwards to the brain and heart, causeth there a resistance, or counter-pressure, or endeavour of the heart, to deliver itself: which endeavour because *outward*, seemeth to be some matter without. And this *seeming*, or *fancy* is that which men call *sense” (Leviathan, ch.1).
Cavendish characterizes that as an account in terms of pressure and reaction. And she responds thus: “I will not say, that there is no pressure or reaction in nature, but pressure and reaction does not make perception, for the sensitive and rational parts of matter make all perception and variety of motion” (PL 1.18). Cavendish, in effect, reverses the order of explanation: where Hobbes thought that pressure and reaction explained perception and thought, Cavendish thinks that perception and thought explain pressure and reaction.
That change is connected, I think, with a second disagreement. Cavendish doesn’t just disagree with Hobbes about which are the correct natural philosophical explanations. She also approaches the search for explanations in a different way, with a different basic model in mind. For the mechanist, the basic models are provided by examples like the workings of a clock, or perhaps the collisions of billiard balls, or even the motions of screws (as in Descartes’s explanation of magnetism). To explain other, seemingly quite different, phenomena, one looks for processes of these mechanical sorts, perhaps in the small parts of the things involved.
For Cavendish, in contrast, the basic causal model is provided by the human being. The basic model of a causal process is one in which someone perceives, considers, decides, and acts. She too, like the mechanist, needs to explain phenomena that do not obviously fit her basic causal model. But for her, they are the very cases that the mechanists take as basic. Thus the explanation of a collision between two billiard balls will fundamentally involve the second ball’s perceiving the first, deciding what to do in response, and moving off as a result. These processes are not, perhaps, supposed to be exactly the same as those in human beings: one reads of things such as “mineral life and knowledge” and “vegetable knowledge” (PL 2.13). But the human is what we know. And the human agent is the model for thinking about everything else.
Thus, for both Cavendish and her mechanist opponents, groups of commitments are bundled together. Explanations in natural philosophy, ontological commitments to what sorts of things there are in the natural world, and methodological commitments to sorts of explanations to look for, are all interconnected. Often one is not obviously prior to the others. But Cavendish’s rejection of mechanist views did not just involve a disagrement on the natural philosophical explanations, but also, I suggest, a disagreement on this methodological issue of what one’s most basic models for understanding the world are. And the influence of this new model goes quite far. Thus, in explaining the perception of sound, Cavendish considers some ways it can be inaccurate:
for if it be, that the motions are tired with figuring … then they move slowly and weakly, not that they are tired and weak in strength, but with working and repeating one and the same object, and so through love to variety, change from working regularly to move irregularly, so as not to pattern outward objects as they ought (PL 1.22)
Note this: “motions are tired with figuring”. It’s not just a thinking thing that is the model here, but a human being who can become tired with things because they are repetitious, perhaps tediously so.
 Helpful discussions in the secondary literature include Eileen O’Neill’s discussion in the introduction to her edition of Cavendish’s Observations upon Experimental Philosophy, and Karen Detlefsen’s discussions in papers including “Reason and Freedom: Margaret Cavendish on the Order and Disorder of Nature”. I don’t want to disagree in any major way (I don’t think) — rather I want to explore a different way of framing what Cavendish is up to.