Happy Body

"How does Spinoza define a body? A body, of whatever kind, is defined by Spinoza in two simultaneous ways. In the first place, a body, however small it may be, composed of an infinite number of particles; it is a relations of motions and rest, of speeds and slowness between particles, that define a body. Secondly, a body affects other bodies, or is affected, that also defines a body in its individuality."

Gilles Deleuze