Benedictus de Spinoza 
Ethics — Part 1 

DEFINITIONS.

I. By that which is 'self-caused' I mean that of which the essence involves existence, or that of which the nature is only conceivable as existent.

II. A thing is called 'finite after its kind' when it can be limited by another thing of the same nature; for instance, a body is called finite because we always conceive another greater body. So, also, a thought is limited by another thought, but a body is not limited by thought, nor a thought by body.