Johann Wolfgang von Goethe, in a conversation with Sulpiz Boisserée, 3 August 1815. As quoted in Julie D. Prandi's “Dare To Be Happy!”: A Study of Go… - Benedictus de Spinoza

Descartes defined matter in terms of extension. It could just as well be defined in terms of time, for both the one and the other are external conditions of its existence in spatial and temporal relations. Thus both become also the necessary conditions of measurement for all thinking minds, which are themselves limited by place and time, but they never become the essence of matter. Spinoza struggled for a long time against this Cartesian explanation, probably because he felt that something about it was not clear. He was not satisfied with his teacher's sharp distinction between matter and spirit, but, since he lacked a unifying intermediate conception, what could he do? Unfortunately then, in his Ethics he still took matter for extension, that is space, and set it up beside thought, an entirely different kind of thing. Now he was indeed on the way to a very intricate confusion.

Spinoza founds Modern materialism in its highest form, determining the horizons of both Modern and contemporary philosophical speculation within an immanent and given philosophy of being and an atheism defined as the negation of every presupposed ordering of either the constitution of being or human behavior. However, even in its productive and living form, Spinozian metaphysics does not succeed in superseding the limits of a purely "spatial" (or Galilean-physical) conception of the world. It certainly pushes on this conception and tries to destroy its limits, but it does not reach a solution. Rather, it leaves unresolved the problem of the relationship between the spatial dimensions and the temporal, creative, and dynamic dimensions of being. The imagination, that spiritual faculty running throughout the Spinozian system, constitutes being in an order that is only allusively temporal. As such, the problem remains intact, in terms that are unresolved but pure and forceful: Being (before the invention of the dialectic) evades the tangle of dialectical materialism. In fact, the readings of Spinoza by socialist and Soviet authors have not enriched dialectical materialism but have, rather, only diminished the potentialities that Spinozian metaphysics offers for superseding the purely spatial and objectivistic dimension of materialism.

Will and intellect are one and the same thing.