“Rank beliefs not according to their plausibility but by the harm they may cause.”

Lecture V: Morals
A Course of Popular Lectures (1829)

Source: The Bed of Procrustes: Philosophical and Practical Aphorisms (2010), p. 66

Speech in Leeds (13 March 1925), quoted in On England, and Other Addresses (1926), pp. 62-63.
1925
Context: It was for that reason, feeling as I did, that I was driven into the course which I embraced in December, 1916, when I accepted Mr. Bonar Law's offer to serve as his Parliamentary Secretary. I did that deliberately, because I believed that at my time of life, having already sufficient means to be independent of the active business in which I had passed my life up to then, I had the opportunity of giving my services to the country without any feeling that it was necessary to be remunerated for them. There is nothing singular in that. There must have been millions of men who felt as I did. I have never said, or believed, that that service which I had the opportunity of rendering was one whit higher or better than any other. All service ranks the same, according to the spirit in which it is performed. One of the sources of the great strength of our country in every part of the kingdom is that there are men who have no personal ambition for themselves to get where the limelight is brightest and publicity is greatest. And as long as our country can go on producing that type, which I am thankful to say it is producing from all classes of the community— so long as that is the case, I should never despair of England.

Memoirs of a Revolutionist (1899) http://dwardmac.pitzer.edu/anarchist_archives/kropotkin/memoirs/memoirstoc.html Part IV, Sect. 3 http://dwardmac.pitzer.edu/anarchist_archives/kropotkin/memoirs/memoirs4_3.html
Context: Belief in an ice-cap reaching Middle Europe was at that time rank heresy; but before my eyes a grand picture was rising, and I wanted to draw it, with the thousands of details I saw in it; to use it as a key to the present distribution of floras and faunas; to open new horizons for geology and physical geography.
But what right had I to these highest joys, when all around me was nothing but misery and struggle for a mouldy bit of bread; when whatsoever I should spend to enable me to live in that world of higher emotions must needs be taken from the very mouths of those who grew the wheat and had not bread enough for their children? From somebody's mouth it must be taken, because the aggregate production of mankind remains still so low.
Knowledge is an immense power. Man must know. But we already know much! What if that knowledge — and only that — should become the possession of all? Would not science itself progress in leaps, and cause mankind to make strides in production, invention, and social creation, of which we are hardly in a condition now to measure the speed?

Source: The Book of Pastoral Rule, p.32

Counterterrorism and Cybersecurity: Total Information Awareness (2nd Edition), 2015