For Spinoza, the mind and the body are the same substance. In this manner, personality and body are ontologically the same thing, the same reality or substance. The mind is conjoined from the body, and vice versa. He says, " he mind is united to the body because the body is the object of the mind" (Ethics 2, prop 21). The mind and body are not causally related but rather naturally related, so we can 't say that one decides the other. Spinoza says that, " he body cannot determine the mind to think, nor the mind the body to remain in motion or at rest" (Ethics 3, 2). This is on the grounds that both mind and body act at the same time with the other, so it is irrational to say one decides the other. …show more content…
For Descartes, the mind and the body are autonomous substances, each ready to exist without the other. He gladly demonstrates this starting in the second meditation when he infers that we can be uncertain about the body but not about a reasoning personality since this is what is doing the questioning in the first place. Since we can doubt the body’s existence, and the mind can ‘question’ without a body, we are presented with duality between mind and body. He states, "there is a great difference between mind and body", because the body is divisible while the mind is not. I can, in my mind, divide extended things into parts, but "when I consider the mind, that is, myself insofar as I am only a thing that thinks, I cannot distinguish any parts in me; rather I take myself to be one distinct thing" (Meditation 6,