The Duchess of Dis(Unity)

Many early modern philosophers, such as René Descartes, Henry More, Ralph Cudworth, Gottfried Wilhelm Leibniz, and Samuel Clarke, argue that our minds exhibit a form of unity or oneness that differs from anything we discover in material things. In the Meditations on First Philosophy, for example, Descartes argues that because one and the same I or mind incorporates diverse mental states in a single mental life—such as doubting, understanding, desiring, denying, willing, imagining, and sensing—it follows that this I or mind lacks parts and, therefore, is an immaterial thing. In the Immortality of the Soul, Henry More similarly argues that a materialist cannot explain how a single person can see, hear, and taste all at once, since the integration of diverse perceptions into a single mental life requires a degree of unity beyond anything matter can achieve (Immortality II.2.2, 125-6). Therefore, More concludes, “there is something in us Immaterial or Incorporeall” that binds our perceptions together (Immortality II.2.2, 125-6). We can summarize this argument as follows:

 

1.     Our minds exhibit a special kind of unity or oneness.

2.     A material thing cannot exhibit this kind of unity.

Therefore,

3.     Our minds are not material.

 

Proponents of this argument can allow that material things are unified in a sense: that bricks may be cemented together, strands of rope braided, and that a clock’s gears and springs can interact in complex and coordinated ways. Their contention is that the special kind of unity or oneness we discover in our mental lives—or, better, the multiplicity in unity—cannot occur in matter.

 

More’s argument poses a prima facie threat to Margaret Cavendish’s unorthodox brand of materialism. We know that Cavendish was familiar with this argument as she responds to it in Philosophical Letters II.xiii. Cavendish maintains that she can account for the various kinds of mental unity her dualist opponents identify, despite her thoroughgoing materialism about the natural world. Cavendish argues that an appropriately structured quantity of matter is just as good a candidate for unifying diverse mental states into a single mental life as a simple substance, especially given the distinctive capacities—freedom and rationality—that she attributes to matter. Cavendish does not merely respond to More’s argument, however. She turns it upside down. Cavendish notes that we are often torn, of two minds, and divided against ourselves. She takes these features of our mental lives to reveal our material nature. In other words, she argues as follows:

 

1.     Our minds exhibit various kinds of division or multiplicity.

2.     Only a material thing can exhibit these kinds of division or multiplicity.

Therefore,

3.     Our minds are material.

 

Cavendish identifies four kinds of mental division, each of which she takes to suffice as proof of the mind’s materiality: (a) multimodal experiences, as when someone sees, hears, and tastes all at once, (b) emotional or passionate conflict, as when someone loves and hates the same thing at the same time, (c) the obscurity of our thoughts, and (d) the fact that bodily awareness reveals some parts of our bodies but not others. Cavendish argues that these forms of multiplicity imply that the mind has parts, and that having parts is both necessary and sufficient for materiality (OEP 161, 263). Multiplicity—and, specifically, a multiplicity of parts—is the mark of the material for Cavendish, and the mental bears this mark.

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