The endeavor to understand is the first and only basis of virtue.

I have tried sedulously not to laugh at the acts of man, nor to lament them, nor to detest them, but to understand them.

Anyone who seeks for the true causes of miracles, and strives to understand natural phenomena as an intelligent being, and not to gaze at them like a fool, is set down and denounced as an impious heretic.

I shall consider human actions and desires in exactly the same manner, as though I were concerned with lines, planes and solids.

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.

Indulge yourself in pleasures only in so far as they are necessary for the preservation of health.

Reason connot defeat emotion, an emotion can only be displaced or overcome by a stronger emotion.