Spinoza’s “The Ethics (Book III)”
Book III of Spinoza’s monumental Ethics concerns the affects. After arguing that thought and extension are merely two modes of a single substance, God/Nature, now he needs to cash out what this means for the now thoroughly embodied mind. What results is a ‘geometric psychology’. For those critics who would argue that an extended body, with its rules, and the methods best for describing these, is incapable of thought, speech, art and rational action, Spinoza replies that we do not yet know what a body can do.
For Spinoza’s radical monism, action and thought stand no longer opposed, but are now two ways of conceiving the same event. Accordingly, the body’s ability to act is extended by the mind producing what Spinoza calls adequate ideas, which are themselves based on relations that include at least two bodies – and it undergoes the actions of other things insofar as its ideas are inadequate.1placeholder Implicit in this is the vice-versa: nothing can extend or hinder the body’s powers without also thereby extending or hindering the mind’s power of thought.
Proposition by numbered proposition, with geometrical demonstrations, Spinoza preempts cognitive science and rational psychology, giving the body perhaps its first non-prejudiced philosophical hearing. To read more about Spinoza’s theory of the affects, see Spinoza and “Anti-Oedipus.” On Desiring One’s Own Suppression by Timofei Gerber.
“For, from the standpoint of nature or God, there are always relations that compound, and nothing but relations that compound in accordance with eternal laws. Whenever an idea is adequate, it precisely captures at least two bodies, mine and another, insofar as they compound their relations (“common notion”). On the other hand, there is no adequate idea of bodies that disagree, no adequate idea of a body that disagrees with mine, insofar as it disagrees. In this sense, evil, or rather bad, only exists in terms of inadequate ideas and in the affections of sadness that follow from them (hatred, anger, etc.)” (Gilles Deleuze, Spinoza, Practical Philosophy, City Light Books, 1988, p. 36).