These from Seneca…

“Each day acquire something that will fortify you against poverty, against death, indeed against other misfortunes as well; and after you have run over many thoughts, select one to be thoroughly digested that day.”

“Difficulties strengthen the mind, as labor does the body.”

“It is not that we have so little time but that we lose so much. ... The life we receive is not short but we make it so; we are not ill provided but use what we have wastefully.”

“Leisure without books is death, and burial of a man alive.”

“Withdraw into yourself, as far as you can. Associate with those who will make a better man of you. Welcome those whom you yourself can improve. The process is mutual; for men learn while they teach.”

“errare humanum est, sed perseverare diabolicum: 'to err is human, but to persist (in the mistake) is diabolical.”

“We should every night call ourselves to an account;
What infirmity have I mastered today?
What passions opposed? What temptation resisted? What virtue acquired? Our vices will abort of themselves if they be brought every day to the shrift.”

“I am not born for one corner; the whole world is my native land.”

“It's not because things are difficult that we dare not venture. It's because we dare not venture that they are difficult.”