The Change in Terminology and the Translation Problem

The innovative nature of Spinoza's theory is first expressed at the level of vocabulary through the substitution of the word ‘affectus’ for ‘emotio’ or ‘passio’ to refer to affective movements in people. In Spinoza, the main concept is no longer emotion, but affect. This change in terminology, however, must not be understood as a sweeping innovation or as a radical rejection. On the one hand, the term affectus already appears in Descartes and refers to passion or emotion in its double psychophysiological dimension. This is what emerges from the Latin text of the Principles of Philosophy, particularly §190 in which Descartes tackles the affects of the soul (animi affectibus) as well as natural appetites, and first equates emotions, passions and affects, then affects and passions. On the other hand, the concept of emotion, although rare, is present in Spinoza, and it is synonymous with affect. Thus, in Part IV of the Ethics, he says that ‘the true knowledge of good and evil arouses disturbances of the mind (animi commotiones)’. Now, since the true knowledge of good and evil is defined as an affect, it is clear that the terms are interrelated and overlapping. Spinoza himself corroborates this conclusion by equating affects and emotions on several occasions, such as in Proposition 2 of Ethics V, where he refers to ‘emotions, or affects’ (animi commotionem, seu affectum); in the Scholium to Proposition 20 of Ethics V, where he maintains that ‘when we compare the affects of one and the same man with each other, and find that he is affected, or moved (affici sive moveri) more by one affect than by another’; and in Political Treatise, I, 4, where he asserts that he has

Although there is no reason to pit affectus and commotio against each other, the broad use of the first term rather than the second serves to draw our attention to the originality of Spinoza's definition.