Affect (philosophy) - in Deleuze and Guattari

In Deleuze and Guattari

The terms "affect" and "affection" came to prominence in Gilles Deleuze and Félix Guattari's A Thousand Plateaus, the second volume of Capitalism and Schizophrenia. In his notes on the terminology employed, the translator Brian Massumi gives the following definitions of the terms as used in the volume:

AFFECT/AFFECTION. Neither word denotes a personal feeling (sentiment in Deleuze and Guattari). L'affect (Spinoza's affectus) is an ability to affect and be affected. It is a prepersonal intensity corresponding to the passage from one experiential state of the body to another and implying an augmentation or diminution in that body's capacity to act. L'affection (Spinoza's affectio) is each such state considered as an encounter between the affected body and a second, affecting, body (with body taken in its broadest possible sense to include "mental" or ideal bodies).

Affects, according to Deleuze, are not simple affections, as they are independent from their subject. Artists create affects and percepts, "blocks of space-time", whereas science works with functions, according to Deleuze, and philosophy creates concepts.