I tell my students to try early in life to find an unattainable objective.

The only use for an atomic bomb is to keep somebody else from using one. It can give us no protection - only the doubtful satisfaction of retaliation...

A scientist should be the happiest of men. Not that science isn't serious; but as everyone knows, being serious is one way of being happy, just as being gay is one way of being unhappy.

The only point of government is to safeguard and foster life.

A scientist is in a sense a learned small boy. There is something of the scientist in every small boy. Others must outgrow it. Scientists can stay that way all their lives.

Dropping those atomic bombs on Hiroshima and Nagasaki was a war crime.

There's life all over this universe, but the only life in the solar system is on earth, and in the whole universe we are the only men.