“Injustice anywhere is injustice everywhere. As long as one person suffers unjustly, the whole world suffers. The existence of injustice, violence, and exploitation contaminates and diminishes the whole human community.”

1960s, The Rising Tide of Racial Consciousnes (1960)
Context: Injustice anywhere is a threat to justice everywhere. Therefore, no American can afford to be apathetic about the problem of racial justice. It is a problem that meets every man at his front door.

Similar to Quran 5:32, as quoted in 1,000 Days in Prison: Narges Mohammadi Condemns Iranian Judiciary’s “Subservience” to Security Agencies https://www.iranhumanrights.org/2018/02/1000-days-in-prison-narges-mohammadi-condemns-iranian-judiciarys-subservience-to-security-agencies/ (February 21, 2018), Center for Human Rights in Iran.

The Personality of Jesus (1932)
Context: None of the three ways of dealing with social injustice can entirely prevent or remove human suffering. Resistance by violence tends to increase and intensify suffering; inaction or failure to exert effective restraint perpetuates the misery of the victims of crime or exploitation; non-violent coercion likewise often results in suffering. The policy of wisdom is to use that method which involves a minimum of suffering, and which offers a maximum of redemption.

L'amour de la justice n'est en la plupart des hommes que la crainte de souffrir l'injustice.
Maxim 78.
Reflections; or Sentences and Moral Maxims (1665–1678)

Source: The Culture of Make Believe (2003), p. 19

Source: The Wealth of Nations (1776), Book IV, Chapter III, Part II, p. 531.
Context: The violence and injustice of the rulers of mankind is an ancient evil, for which, I am afraid, the nature of human affairs can scarce admit a remedy.

Encyclical Letter Spe Salvi of the Supreme Pontiff Benedict XVI to the Bishops Priests and Deacons Men and Women Religious and All the Lay Faithful On Christian Hope, 30 November 2007
2007

Part II: The Banality of Slavery, page 65.
Going Postal: Rage, Murder, and Rebellion, From Reagan's Workplaces to Clinton's Columbine and Beyond (2005)
Context: Just as the American colonials' consciousness expanded from rebelling against unfair taxation in the 1760s to wide noble revolutionary goals touching on the inherent rights of mankind, so the Whiskey Rebellion guerrillas took on broader themes as injustice increasingly framed their consciousness. Once you start seeing injustice in one place, it's like taking off blinders- you start to see injustice everywhere, and how it is all connected.