Mediocrity makes the most of its native possessions.

Concupiscence and force are the source of all our actions; concupiscence causes voluntary actions, force involuntary ones.

If it is an extraordinary blindness to live without investigating what we are, it is a terrible one to live an evil life, while believing in God

To find recreation in amusement is not happiness.

Knowledge has two extremes. The first is the pure natural ignorance in which all men find themselves at birth. The other extreme is that reached by great minds, who, having run through all that men can know, find they know nothing, and come back again to that same natural ignorance from which they set out; this is a learned ignorance which is conscious of itself.

You see, if the height of the mercury [barometer] column is less on the top of a mountain than at the foot of it (as I have many reasons for believing, although everyone who has so far written about it is of the contrary opinion), it follows that the weight of the air must be the sole cause of the phenomenon, and not that abhorrence of a vacuum, since it is obvious that at the foot of the mountain there is more air to have weight than at the summit, and we cannot possibly say that the air at the foot of the mountain has a greater aversion to empty space than at the top.

I can well conceive a man without hands, feet, head. But I cannot conceive man without thought; he would be a stone or a brute.