“Better be wise by the misfortunes of others than by your own.”

Source: The Death of King Arthur: A New Verse Translation

Source: The Son of Tarzan

The Better Part (1901)
Context: No man who believes in force and violence is an Anarchist. The true Anarchist decries all influences save those of love and reason. Ideas are his only arms.
Being an Anarchist I am also a Socialist. Socialism is the antithesis of Anarchy. One is the North Pole of Truth, the other the South. The Socialist believes in working for the good of all, while Anarchy is pure Individualism. I believe in every man working for the good of self; and in working for the good of self, he works for the good of all. To think, to see, to feel, to know; to deal justly; to bear all patiently; to act quietly; to speak cheerfully; to moderate one's voice — these things will bring you the highest good. They will bring you the love of the best, and the esteem of that Sacred Few, whose good opinion alone is worth cultivating. And further than this, it is the best way you can serve Society — live your life. The wise way to benefit humanity is to attend to your own affairs, and thus give other people an opportunity to look after theirs.
If there is any better way to teach virtue than by practicing it, I do not know it.
Would you make men better — set them an example. The millenium will never come until governments cease from governing, and the meddler is at rest. Politicians are men who volunteer the task of governing us, for a consideration. The political boss is intent on living off your labor. A man may seek an office in order to do away with the rascal who now occupies it, but for the most part office-seekers are rank rogues. Shakespeare used the word politician five times, and each time it is synonymous with knave. That is to say, a politician is one who sacrifices truth and honor for policy. The highest motive of his life is expediency — policy. In King Lear it is the "scurvy politician," who through tattered clothes beholds small vices, while robes and furred gowns, for him, covers all.

Variant: And I knew that it was better to live out one's own absurdity than to die for that of others.
Source: Invisible Man (1952), Chapter 25.

Il est plus aisé d'être sage pour les autres que de l'être pour soi-même.
Maxim 132.
Reflections; or Sentences and Moral Maxims (1665–1678)

Source: The Roving Mind (1983), Ch. 25

1963, Address at the Free University of Berlin

ESPN The Magazine, September 2001 http://espn.go.com/talent/danpatrick/s/2001/0822/1242493.html

Introductio ad prudentiam: Part II (1727), Gnomologia (1732)