“Men in plural […] can experience meaningfulness only because they can talk with and make sense to each other and themselves.”

In reference to the Alabama Council on Human Relations, an organization which was joined by King, whose church's meeting room was used to hold monthly meetings for the Montgomery chapter the council. Stride Toward Freedom: The Montgomery Story (1958)
1950s
Context: Although the Montgomery council never had a large membership, it played an important role. As the only truly interracial group in Montgomery, it served to keep the desperately needed channels of communication open between the races.
Men often hate each other because they fear each other; they fear each other because they don't know each other; they don't know each other because they can not communicate; they can not communicate because they are separated. In providing an avenue of communication, the council was fulfilling a necessary condition for better race relations in the South.

Ce qui fait que les amants et les maîtresses ne s'ennuient point d'être ensemble, c'est qu'ils parlent toujours d'eux-mêmes.
Variant translation: What makes lovers and their mistresses never weary of being together is that they are always talking about themselves.
Maxim 312.
Reflections; or Sentences and Moral Maxims (1665–1678)

1970s, The argument: causality in the electric world (1973)

Attributed to Kenneth Boulding in Hans Adriaansens (1980) Talcott Parsons and the Conceptual Dilemma. p. 10
1980s

Source: Moral Man and Immoral Society (1932), pp. 8-9
Context: 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 which makes the actions of collective man an outrage to their conscience. 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.

Source: The Social Function of Science (1939), p. 415-416. Chapter XVI. THE SOCIAL FUNCTION OF SCIENCE. The Transformation of Science

Truman Library address (2006)
Context: No nation can make itself secure by seeking supremacy over all others. We all share responsibility for each other’s security, and only by working to make each other secure can we hope to achieve lasting security for ourselves.
— And, I would add that this responsibility is not simply a matter of States being ready to come to each other’s aid when attacked — important though that is. It also includes our shared responsibility to protect populations from genocide, war crimes, ethnic cleansing and crimes against humanity — a responsibility solemnly accepted by all nations at last year’s UN world summit. That means that respect for national sovereignty can no longer be used as a shield by Governments intent on massacring their own people, or as an excuse for the rest of us to do nothing when heinous crimes are committed.

Source: 4.48 Psychosis