Meaning of “Insanity in individuals is something rare—but in groups,…”

The Subjection of Women (1869), Chapter II, printed page 79, Project Gutenberg #27083. Mill contrasts command-and-obedience relations with equal association and states that society in equality is the normal state toward which improving social relations should move.

The Joyful Wisdom, aphorism 274; Thomas Common translation.

Rights of Man, Part I, Conclusion; represented from Moncure Daniel Conway’s public-domain Project Gutenberg #3742 collection. The passage attributes national hostility to old systems of government rather than to an inevitable enmity between people.

Rights of Man, Part II; the surrounding passage attributes much ordinary social coordination to society itself.

A Philosophical Dictionary, article ‘Toleration,’ Section I, Project Gutenberg #35630. Voltaire opens the section by calling toleration an attribute of humanity and urging mutual pardon for human weakness and error, then turns immediately to religious communities trading together without violence. This remains an Enlightenment polemic against religious persecution rather than a modern legal definition or universal empirical law.

The Picture of Dorian Gray, 1891 edition, Chapter 17; Lord Henry answers the Duchess of Monmouth’s question “What are you?” with “To define is to limit.”