The time when most of you should withdraw into yourself is when you are forced to be in a crowd.

Neither one should hesitate about dedicating oneself to philosophy when young, nor should get tired of doing it when one's old, because no one is ever too young or too old to reach one's soul's healthy.

Natural justice is a compact resulting from expediency by which men seek to prevent one man from injuring others and to protect him from being injured by them.

There are infinite worlds both like and unlike this world of ours. For the atoms being infinite in number... are borne on far out into space.

The pleasant life is not produced by continual drinking and dancing, nor sexual intercourse, nor rare dishes of sea food and other delicacies of a luxurious table. On the contrary, it is produced by sober reasoning which examines the motives for every choice and avoidance, driving away beliefs which are the source of mental disturbances.

If thou wilt make a man happy, add not unto his riches but take away from his desires.

Earthquakes may be brought about because wind is caught up in the earth, so the earth is dislocated in small masses and is continually shaken, and that causes it to sway.