Mankind must put an end to war - or war will put an end to mankind.

[Address before the United Nations, September 25 1961]

It is an unfortunate fact that we can secure peace only by preparing for war.

It is an unfortunate fact that we can secure peace only by preparing for war.

We set sail on this new sea because there is new knowledge to be gained, and new rights to be won, and they must be won and used for the progress of all people. For space science, like nuclear science and technology, has no conscience of its own. Whether it will become a force for good or ill depends on man, and only if the United States occupies a position of preeminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war.

We're winning the war but we haven't won the war yet. I think whoever takes over this job in 20 years will still have to fight this fight.

If we cannot end now our differences, at least we can help make the world safe for diversity.

[Commencement Address at American University, June 10 1963]