When the mind conceives things which diminish or hinder the body's power of activity, it endeavours, as far as possible, to remember things which exclude the existence of the first--named things.
Proof .-- So long as the mind conceives anything of the kind alluded to, the power of the mind and body is diminished or constrained (cf.III.xii.

Proof); nevertheless it will continue to conceive it, until the mind conceives something else, which excludes the present existence thereof (II.

xvii.); that is (as I have just shown), the power of the mind and of the body is diminished, or constrained, until the mind conceives something else, which excludes the existence of the former thing conceived: therefore the mind (III.

ix.), as far as it can, will endeavour to conceive or remember the latter.

Q.E.D.
Corollary .-- Hence it follows that the mind shrinks from conceiving those things, which diminish or constrain the power of itself and of the body.
Note .-- From what has been said we may clearly understand the nature of Love and Hate.