The hardest thing of all is to find a black cat in a dark room, especially if there is no cat.

he who will not economize will have to agonize

If things far away don’t concern you, you’ll soon mourn things close at hand.

Reviewing what you have learned and learning anew, you are fit to be a teacher.

Those who know the TRUTH are not equal to those who love it.

To study and not think is a waste. To think and not study is dangerous.