Learning without thought is labor lost; thought without learning is perilous.

Learn as though you would never be able to master it; hold it as though you would be in fear of losing it.

If I am walking with two other men, each of them will serve as my teacher. I will pick out the good points of the one and imitate them, and the bad points of the other and correct them in myself.

There is the love of knowing without the love of learning; the beclouding here leads to dissipation of mind.

Learning without thought is labor lost; and thought without learning is perilous.

At fifteen I set my heart upon learning.
At thirty, I had planted my feet firm upon the ground.
At forty, I no longer suffered from perplexities.
At fifty, I knew what were the biddings of Heaven.
At sixty, I heard them with docile ear.
At seventy, I could follow the dictates of my own heart; for what I desired no longer overstepped the boundaries of right.