Definitions

I now explain the results from God’s essence, which are able to lead us, as it were by the hand, to the knowledge of the human mind and its highest blessedness.

Definitions

1. Body is a mode which expresses in a certain determinate manner the essence of God, in so far as he is considered as an extended thing. (See Pt. 1, Prop. 25, Coroll.)

2. A thing’s essence is that which inseparable from the thing. being given, the thing is necessarily given also, and, which being removed, the thing is necessarily removed also.

• Without a thing’s essence, the thing cannot cannot exist nor be conceived.
• Without the thing, the thing’s essence also cannot exist nor be conceived.

3. Idea is the mental conception formed by the mind as a thinking thing. Explanation= I say conception instead of perception, because ‘perception’ seems to imply that the mind is passive in respect to the object; whereas conception seems to express an activity of the mind.

4. An adequate idea is an idea which in itself, without relation to the object, has all the properties or intrinsic marks of a true idea. Explanation= I say intrinsic, in order to exclude that mark which is extrinsic or the agreement between the idea and its object (ideatum).

5. Duration is the indefinite continuance of existing. Explanation= I say indefinite, because it cannot be determined through the existence itself of the existing thing, or by its efficient cause, which necessarily gives the existence of the thing, but does not take it away.

6. I use reality and perfection as synonymous terms. Definition 7= Particular things are things which are finite and have a conditioned existence. But if several individual things concur in one action, so as to be all simultaneously the effect of one cause, I consider them all as one particular thing.

Axioms

1. Man’s essemce does not involve necessary existence. It may come to pass that this or that man does or does not exist.

2. Man thinks.

3. Modes of thinking, such as love, desire, or any passion, only happens when an idea of the thing loved, desired, etc. is in the same individual. But the idea can exist without the presence of any other mode of thinking.

4. We perceive that a certain body is affected in many ways. 5. We feel and perceive no particular things, except bodies and modes of thought. Note= The Postulates are given after the conclusion of Prop. 13.