Whatever increases, decreases, limits or extends the body's power of action, increases decreases, limits, or extends the mind's power of action. And whatever increases, decreases, limits, or extends the mind's power of action, also increases, decreases, limits, or extends the body's power of action.

I should attempt to treat human vice and folly geometrically... the passions of hatred, anger, envy, and so on, considered in themselves, follow from the necessity and efficacy of nature... I shall, therefore, treat the nature and strength of the emotion in exactly the same manner, as though I were concerned with lines, planes, and solids.

None are more taken in by flattery than the proud, who wish to be the first and are not.

But if men would give heed to the nature of substance they would doubt less concerning the Proposition that Existence appertains to the nature of substance: rather they would reckon it an axiom above all others, and hold it among common opinions. For then by substance they would understand that which is in itself, and through itself is conceived, or rather that whose knowledge does not depend on the knowledge of any other thing.

Blessedness is not the reward of virtue but virtue itself.

If we conceive that anyone loves, desires, or hates anything which we ourselves love, desire, or hate, we shall thereupon regard the thing in question with more steadfast love, etc. On the contrary, if we think that anyone shrinks from something that we love, we shall undergo vacillation of the soul.

It is not possible that we should remember that we existed before our body, for our can bear no trace of such existence, neither can eternity be defined in terms of time or have any relation to time. But notwithstanding, we feel and know that we are eternal.