Karl Paul Reinhold Niebuhr (1892-06-21- 1971-06-01) was an American Protestant theologian best known for his efforts to relate the Christian faith to the realities of politics and diplomacy. He is a crucial contributor to modern thinking about what a just war would be.

Sourced

• Man's capacity for justice makes democracy possible, but man's inclination to injustice makes democracy necessary.
  • The Children of Light and the Children of Darkness (1944)

Moral Man and Immoral Society (1932)

Moral Man and Immoral Society: A Study of Ethics and Politics, Charles Scribner's Sons (1932)

• This insinuation of the interests of the self into even the most ideal enterprises and most universal objectives, envisaged in moments of highest rationality, makes hypocrisy an inevitable by product of all virtuous endeavor.

• Man is endowed by nature with organic relations to his fellow men; and natural impulse prompts him to consider the needs of others even when they compete with his own.

• [R]eason tends to check selfish impulses and to grant the satisfaction of legitimate impulses in others.

• The measure of our rationality determines the degree of vividness with which we appreciate the needs of other life, the extent to which we become conscious of the real character of our own motives and impulses, the ability to harmonize conflicting impulses in our own life and in society, and the capacity to choose adequate means for approved ends.

• While it is possible for intelligence to increase the range of benevolent impulse, and thus prompt a human being to consider the needs and rights of other than those to whom he is bound by organic and physical relationship, there are definite limits in the capacity of ordinary mortals which makes it impossible for them to grant to others what they claim for themselves.

• Reason is not the sole basis of moral virtue in man. His social impulses are more deeply rooted than his rational life.

• The will-to-live becomes the will-to-power.

• The individual or the group which organizes any society, however social its intentions or pretensions, arrogates an inordinate portion of social privilege to itself.

• The society in which each man lives is at once the basis for, and the nemesis of, that fulness of life which each man seeks.

• Human beings are endowed by nature with both selfish and unselfish impulses.

• All social cooperation on a larger scale than the most intimate social group requires a measure of coercion.

• The inevitable hypocrisy, which is associated with the all the collective activities of the human race, springs chiefly from this source: that individuals have a moral code with make the actions of collective man an outrage to their conscious. They therefore invent romantic and moral interpretations of the real facts, preferring to obscure rather than reveal the true character of their collective behavior. Sometimes they are as anxious to offer moral justifications for the brutalities from which they suffer as for those which they commit. The fact that the hypocrisy of man's group behavior... expresses itself not only in terms of self-justification but in terms of moral justification of human behavior in general, symbolizes one of the tragedies of the human spirit: its inability to conform its collective life to its individual ideals. As individuals, men believe they ought to love and serve each other and establish justice between each other. As racial, economic and national groups they take for themselves, whatever their power can command.

The Nature and Destiny of Man: A Christian Interpretation (1941)

The Nature and Destiny of Man: A Christian Interpretation, from the Gifford Lectures, (1941)

• Human existence is obviously distinguished from animal life by its qualified participation in creation. Within limits it breaks the forms of nature and creates new configurations of vitality. Its transcendence over natural process offers it the opportunity of interfering with the established forms and unities of vitality as nature knows them.

• The modern man is . . . certain about his essential virtue . . . [and since] he does not see that he has a freedom of spirit which transcends both nature and reason . . . [he] is unable to understand the real pathos of his defiance of nature's and reason's laws. He always imagines himself betrayed into this defiance either by some accidental corruption in his past history or by some sloth of reason. Hence he hopes for redemption, either through a program of social reorganization or by some scheme of education.

• The brotherhood of the community is indeed the ground in which the individual is ethically realized. But the community is the frustration as well as the realization of individual life. Its collective egotism is an offense to his conscience; its institutional injustices negate the ideal of justice; and such brotherhood as it achieves is limited by ethnic and geographic boundaries. Historical communities are, in short, more deeply involved in nature and time than the individual.

The Serenity Prayer

This statement, or variants of it, have often been attributed to others, including St. Francis of Assisi, but without sources. Though similar prayers may have existed, the work seems to be Niebuhr's. He never copyrighted the prayer, and it has been used in many variants.

• God, give us grace to accept with serenity
  the things that cannot be changed,
  courage to change the things
  which should be changed,
  and the wisdom to distinguish
  the one from the other.

  Living one day at a time,
  Enjoying one moment at a time,
  Accepting hardship as a pathway to peace,
  Taking, as Jesus did,
  This sinful world as it is,
  Not as I would have it,
  Trusting that You will make all things right,
  If I surrender to Your will,
  So that I may be reasonably happy in this life,
  And supremely happy with You forever in the next.
  Amen.

  • Full version of the original (ca. 1942)

• God, give us grace to accept with serenity
  the things that cannot be changed, courage
  to change the things which should be changed,
  and the wisdom to distinguish the one from the other.
  • Niebuhr's preferred form, as declared by his widow

• God grant me the serenity
  to accept the things I cannot change,
  courage to change the things I can,
  and the wisdom to know the difference.
  • One of the most commonly quoted forms.

The Irony of American History (1952)

The Irony of American History, Charles Scribner’s Sons (1952)

• [The value and dignity of the individual] is threatened whenever it is assumed that individual desires, hopes and ideals can be fitted with frictionless harmony into the collective purposes of man. The individual is not discrete. He cannot find his fulfillment outside of the community; but he also cannot find fulfillment completely within society. In so far as he finds fulfillment within society he must abate his individual ambitions. He must 'die to self' if he would truly live. In so far as he finds fulfillment beyond every historical community he lives his life in painful tension with even the best community, sometimes achieving standards of conduct which defy the standards of the community with a resolute "we must obey God rather than man."

• We take, and must continue to take, morally hazardous actions to preserve our civilization. We must exercise our power. But we ought neither to believe that a nation is capable of perfect disinterestedness in its exercise, nor become complacent about a particular degree of interest and passion which corrupt the justice by which the exercise of power is legitimatized.

• Our dreams of bringing the whole of human history under the control of the human will are ironically refuted by the fact that no group of idealists can easily move the pattern of history toward the desired goal of peace and justice. The recalcitrant forces in the historical drama have a power and persistence beyond our reckoning.

• Our dreams of a pure virtue are dissolved in a situation in which it is possible to exercise the virtue of responsibility toward a community of nations only by courting the prospective guilt of the atomic bomb.

• Nothing worth doing is completed in our lifetime; therefore, we are saved by hope. Nothing true or beautiful or good makes complete sense in any immediate context of history; therefore, we are saved by faith. Nothing we do, however virtuous, can be accomplished alone; therefore, we are saved by love. No virtuous act is quite as virtuous from the standpoint of our friend or foe as from our own,; therefore, we are saved by the final form of love, which is forgiveness.