As men are not able to fight against death, misery, ignorance, they have taken it into their heads, in order to be happy, not to think of them at all.

Put the world's greatest philosopher on a plank that is wider than need be; if there is a precipe below, although his reason may convince him that he is safe, his imagination will prevail.

Curiosity is only vanity. Most frequently we wish not to know, but to talk. We would not take a sea voyage for the sole pleasure of seeing without hope of ever telling.

It is certain that the soul is either mortal or immortal. The decision of this question must make a total difference in the principles of morals. Yet philosophers have arranged their moral system entirely independent of this. What an extraordinary blindness!

Just as I do not know where I came from, so I do not know where I am going. All I know is that when I leave this world I shall fall forever into oblivion, or into the hands of an angry God, without knowing which of the two will be my lot for eternity. Such is my state of mind, full of weakness and uncertainty. The only conclusion I can draw from all this is that I must pass my days without a thought of trying to find out what is going to happen to me.

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.

Reverend Fathers, my letters did not usually follow each other at such close intervals, nor were they so long.... This one would not be so long had I but the leisure to make it shorter.