The Mahabharata - pg. 152

Arvavasu and Parvavasu were both sons of a great scholar. Both of them learnt at his feet and became eminent scholars themselves. But learning is one thing and virtue is quite another. It is true that one should know the difference between good and evil, if one is to seek good and shun evil, but this knowledge should soak into every thought and influence every act in one's life. Then indeed knowledge becomes virtue. The knowledge, that is merely so much undigested information crammed into the mind, cannot instill virtue. It is just an outward show like our clothes and is no real part of us.