Definitions

Definitions:

1. Self—caused means something of which the essence involves existence.

2. A thing is finite when it can be limited by another thing of the same nature.

For instance, a body is finite because we always conceive another greater body. A thought is limited by another thought. But a body is not limited by thought, nor a thought limited by a body.

3. Substance is something in itself and conceived through itself. In other words, something of which a conception can be formed independently of any other conception.

4. Attribute is something which the intellect perceives as constituting the essence of substance.

5. Mode are the modifications of substance, or that which exists in, and is conceived through, something other than itself.

6. God means a being absolutely infinite. It is a substance consisting in infinite attributes, of which each expresses eternal and infinite essentiality. I say absolutely infinite, not infinite after its kind, for infinite attributes may be denied for a thing infinite only after its kind. But something absolutely infinite contains in its essence whatever expresses reality and involves no negation.

7. A free thing is something:

• that exists solely by the necessity of its own nature
• that does actions which are determined by itself alone.

8. On the other hand, a thing is necessary, or rather constrained, if it is determined by something external to itself, to a fixed and definite method of existence or action.

9. Eternity means existence itself, in so far as it is conceived necessarily to follow solely from the definition of that which is eternal.

• Existence of this kind is conceived as an eternal truth, like the essence of a thing.
• Therefore, it cannot be explained through continuance or time, though continuance may be conceived without a beginning or end.

Axioms

1. Everything which exists, exists either in itself or in something else.

2. That which cannot be conceived through anything else must be conceived through itself.

3. From a given definite cause, an effect necessarily follows.

   • On the other hand, if there is no definite cause, it is impossible that an effect can follow.

4. The knowledge of an effect depends on and involves the knowledge of a cause.

5. Things which have nothing in common cannot be understood, the one by means of the other.

   • The conception of one does not involve the conception of the other.

6. A true idea must correspond with its ideate or object.

7. If a thing can be conceived as non—existing, its essence does not involve existence.