"If the past has been an obstacle and a burden, knowledge of the past is the safest and the surest emancipation"

"Knowledge of what is possible is the beginning of happiness"

"The seat of knowledge is in the head, of wisdom, in the heart"

"Never stop learning; knowledge doubles every fourteen months"

"The more extensive a man's knowledge of what has been done, the greater will be his power of knowing what to do"

"To know, is to know that you know nothing. That is the meaning of true knowledge"

"Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search for knowledge, and unbearable pity for the suffering of mankind"

"There is no knowledge, no light, no wisdom that you are in possession of, but what you have received it from some source"

"Knowledge speaks, but wisdom listens"

"The study and knowledge of the universe would somehow be lame and defective were no practical results to follow"