“We look upon this shaken Earth, and we declare our firm and fixed purpose — the building of a peace with justice in a world where moral law prevails. The building of such a peace is a bold and solemn purpose. To proclaim it is easy. To serve it will be hard.”

Reasoned Proposal to the Central Committee of the League for Peace and Freedom (1867)

1930s, Quarantine Speech (1937)
Context: Those who cherish their freedom and recognize and respect the equal right of their neighbors to be free and live in peace must work together for the triumph of law and moral principles in order that peace, justice, and confidence may prevail in the world. There must be a return to a belief in the pledged word, in the value of a signed treaty. There must be recognition of the fact that national morality is as vital as private morality.

Broadcast to the Nation, 12 November 1984
Extracts from Speeches

On Sudanese President Omar al Bashir's international arrest warrant. Sudan’s Bashir ‘cancelled visit to Tanzania’ http://thecitizen.co.tz/news/2-international-news/17958-sudans-bashir-cancelled-visit-to-tanzania

1990s, Inaugural celebration address (1994)
Context: We are both humbled and elevated by the honour and privilege that you, the people of South Africa, have bestowed on us, as the first President of a united, democratic, non-racial and non-sexist government.
We understand it still that there is no easy road to freedom
We know it well that none of us acting alone can achieve success.
We must therefore act together as a united people, for national reconciliation, for nation building, for the birth of a new world.
Let there be justice for all.
Let there be peace for all.

Case of Edmonds and others (1821), 1 St. Tr. (N. S.) 899.

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. There is a fascinating little story that is preserved for us in Greek literature about Ulysses and the Sirens. The Sirens had the ability to sing so sweetly that sailors could not resist steering toward their island. Many ships were lured upon the rocks, and men forgot home, duty, and honor as they flung themselves into the sea to be embraced by arms that drew them down to death. Ulysses, determined not to be lured by the Sirens, first decided to tie himself tightly to the mast of his boat, and his crew stuffed their ears with wax. But finally he and his crew learned a better way to save themselves: they took on board the beautiful singer Orpheus whose melodies were sweeter than the music of the Sirens. When Orpheus sang, who bothered to listen to the Sirens? 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.
1960s, The Quest for Peace and Justice (1964)

Nobel Peace Prize Acceptance Speech (2012)
Context: The peace of our world is indivisible. As long as negative forces are getting the better of positive forces anywhere, we are all at risk. It may be questioned whether all negative forces could ever be removed. The simple answer is: “No!” It is in human nature to contain both the positive and the negative. However, it is also within human capability to work to reinforce the positive and to minimize or neutralize the negative. Absolute peace in our world is an unattainable goal. But it is one towards which we must continue to journey, our eyes fixed on it as a traveller in a desert fixes his eyes on the one guiding star that will lead him to salvation. Even if we do not achieve perfect peace on earth, because perfect peace is not of this earth, common endeavours to gain peace will unite individuals and nations in trust and friendship and help to make our human community safer and kinder.

Nobel Peace Prize Lecture (December 10, 2014)