Definition III. By emotion I mean the modifications of the body, whereby the active power of the said body is increased or diminished, aided or constrained, and also the ideas of such modifications.
Proposition I. Our mind is in certain cases active, and in certain cases passive. In so far as it has adequate ideas it is necessarily active, and in so far as it has inadequate ideas, it is necessarily passive.
Proof.—In every human mind there are some adequate ideas, and some ideas that are fragmentary and confused ..
I would further call attention to the mechanism of the human body, which far surpasses in complexity all that has been put together by human art, not to repeat what I have already shown, namely, that from nature, under whatever attribute she be considered, infinite results follow.
Experience teaches us no less clearly than reason, that men believe themselves to be free, simply because they are conscious of their actions, and unconscious of the causes whereby those actions are determined... Those who believe, that they speak or keep silence or act in any way from the free decision of their mind, do but dream with their eyes open.
Comment:
Spinoza ties emotions to action in the world. And to the changes they produce in the brain. In addition he designates the mind as active when it is occupied with true ideas and passive when those ideas are framentary.
Spinoza voices hia desire to treat emotions and human actions just the same as he had done with mind, that is, geometricly with definitions, axioms and postulates. He defines human emotions as an action of the body together with the idea of such action. He distingusiches between emotions and passions. The former being a direct action of the person and the latter something that effects the mind without it being involved.
Spinoza denys personal free will. Without the modern Freudian conception of the unconscious he claims that humans act for reasons hidden from their thought processes.