Concentrate not merely on the negative expulsion of war, but on the positive affirmation of peace
We will not build a peaceful world by following a negative path. It is not enough to say "We must not wage war." It is necessary to love peace and sacrifice for it. We must concentrate not merely on the negative expulsion of war, but on the positive affirmation of peace ...
So we must fix our vision not merely on the negative expulsion of war, but upon the positive affirmation of peace. We must see that peace represents a sweeter music, a cosmic melody that is far superior to the discords of war. Somehow we must transform the dynamics of the world power struggle from the negative nuclear arms race which no one can win to a positive contest to harness man's creative genius for the purpose of making peace and prosperity a reality for all of the nations of the world. In short, we must shift the arms race into a "peace race". If we have the will and determination to mount such a peace offensive, we will unlock hitherto tightly sealed doors of hope and transform our imminent cosmic elegy into a psalm of creative fulfillment.
All that I have said boils down to the point of affirming that mankind's survival is dependent upon man's ability to solve the problems of racial injustice, poverty, and war; the solution of these problems is in turn dependent upon man squaring his moral progress with his scientific progress, and learning the practical art of living in harmony.
MLK Nobel Lecture
http://www.nobelprize.org/nobel_prizes/peace/laureates/1964/king-lecture.html