It was a favorite expression of Theophrastus that time was the most valuable thing that a man could spend.

Dogs and philosophers do the greatest good and get the fewest rewards.

Antisthenes used to say that envious people were devoured by their own disposition, just as iron is by rust. Envy of others comes from comparing what they have with what the envious person has, rather than the envious person realising they have more than what they could have and certainly more than some others and being grateful. It is really just an inability to get a correct perspective on their lives.

Most men are within a finger's breadth of being mad.

All things are in common among friends.

In a rich man's house there is no place to spit but his face.

Protagoras asserted that there are two sides to every question, exactly opposite to each other.