“Those who can bring themselves to renounce wealth, position and power accruing from a social system based on violence and putting a premium on acquisitiveness, and to identify themselves in some real fashion with the struggle of the masses toward the light, may help in a measure — more, doubtless, by life than by words — to devise a more excellent way, a technique of social progress less crude, brutal, costly and slow than mankind has yet evolved.”

Source: The Voice of Destruction (1940), p. 246

Wollen wir etwa die Pädagogik den Philosophen in die Hände spielen? Nichts weniger als das! Sie würden sich ungeschickt genug benehmen. Denen allein werde sie anvertraut, die mehr sind als Philosophen, darum aber auch unendlich mehr als Humanisten oder Realisten.
Source: The False Principle of our Education (1842), p. 19

Introduction : The Success of Socialist Ideas
Socialism (1922)

Einar in "Shepherds' Meet"
Sjálfstætt fólk (Independent People) (1935), Book One, Part I: Icelandic Pioneers

The Meaning of the Russian Revolution (1906) http://archive.org/stream/russianrevolutio00tols/russianrevolutio00tols_djvu.txt
Context: One might think that it must be quite clear to people not deprived of reason, that violence breeds violence; that the only means of deliverance from violence lies in not taking part in it. This method, one would think, is quite obvious. It is evident that a great majority of men can be enslaved by a small minority only if the enslaved themselves take part in their own enslavement. If people are enslaved, it is only because they either fight violence with violence or participate in violence for their own personal profit. Those who neither struggle against violence nor take part in it can no more be enslaved than water can be cut. They can be robbed, prevented from moving about, wounded or killed, but they cannot be enslaved: that is, made to act against their own reasonable will.

Source: Go Set a Watchman

Progress, Coexistence and Intellectual Freedom (1968)
Context: Millions of people throughout the world are striving to put an end to poverty. They despise oppression, dogmatism, and demagogy (and their more extreme manifestations — racism, fascism, Stalinism, and Maoism). They believe in progress based on the use, under conditions of social justice and intellectual freedom, of all the positive experience accumulated by mankind.

Preface
Medieval castles (2005)

Letter to Ludwig Kugelmann http://www.marxists.org/archive/marx/works/1868/letters/68_12_12.htm, dated 12 December 1868.