The value of achievement lies in the achieving.

Only morality in our actions can give beauty and dignity to life.

My only refuge, as a serious young man, from the despair of my financial burden to my family, is that I did everything I could to never permit myself any amusements or diversions except those afforded by my studies.

Scientific greatness is less a matter of intelligence than character; if the scientist refuses to compromise or accept incomplete answers and persists in grappling the most basic and difficult questions.

The physicists say that I am a mathematician, and the mathematicians say that I am a physicist. I am a completely isolated man and though everybody knows me, there are very few people who really know me.

The fear of death is the most unjustified of all fears, for there's no risk of accident for someone who's dead.

Know where to find the information and how to use it - That's the secret of success.