Baruch (Bento, Benedictus) Spinoza (1632 - 1677) was a Dutch philosopher of Portuguese-Jewish origin. Spinoza has earned recognition as one of the great rationalists of 17th-century philosophy mainly due to his Ethics in which he opposed Descartes' mind–body dualism.
For Spinoza, individual things are simply clusters of qualities within regions of space. Just as a blush is merely a confluence of properties on a region of a face, the person is a confluence of properties “on a region” of substance. So, we are temporary, since we are just modes of the one and only substance.
According to Descartes, the term “substance” is used in reference to both God and created substance. Spinoza, however, denies that divine and created substances are different substances. For instance, finite minds are not themselves substances, but rather modes of thinking substance. Spinoza agrees with Descartes that God is the cause of all things. Yet, Spinoza’s god lacks volition and personality. Spinoza regards god not as a cause of a mental act that creates the universe “from the outside” through an act of will, but rather as a cause from whom the universe unfolds out of his own necessity. For him, logically necessary implication is the same as causal connection. Hence, all things follow from logical and causal necessity from God’s eternal and infinite nature.