“Motives do not concern me; they are a dangerous subject with which to deal.”

Preface
1900s, Getting Married (1908)
Context: There is no subject on which more dangerous nonsense is talked and thought than marriage. If the mischief stopped at talking and thinking it would be bad enough; but it goes further, into disastrous anarchical action. Because our marriage law is inhuman and unreasonable to the point of downright abomination, the bolder and more rebellious spirits form illicit unions, defiantly sending cards round to their friends announcing what they have done. Young women come to me and ask me whether I think they ought to consent to marry the man they have decided to live with; and they are perplexed and astonished when I, who am supposed (heaven knows why!) to have the most advanced views attainable on the subject, urge them on no account to compromise themselves without the security of an authentic wedding ring.

Michel Henry, La Barbarie, éd. Grasset, 1987, p. 172
Books on Culture and Barbarism, Barbarism (1987)
Original: (fr) La culture est l'ensemble des entreprises et des pratiques dans lesquelles s'exprime la surabondance de la vie, toutes elles ont pour motivation la « charge », le « trop » qui dispose intérieurement la subjectivité vivante comme une force prête à se prodiguer et contrainte, sous la charge, de le faire.

Variant: When dealing with people, let us remember we are not dealing with creatures of logic. We are dealing with creatures of emotion, creatures bristling with prejudices and motivated by pride and vanity.
Source: How to Win Friends and Influence People

On The Algebra of Logic (1885)
Context: Any character or proposition either concerns one subject, two subjects, or a plurality of subjects. For example, one particle has mass, two particles attract one another, a particle revolves about the line joining two others. A fact concerning two subjects is a dual character or relation; but a relation which is a mere combination of two independent facts concerning the two subjects may be called degenerate, just as two lines are called a degenerate conic. In like manner a plural character or conjoint relation is to be called degenerate if it is a mere compound of dual characters.
A sign is in a conjoint relation to the thing denoted and to the mind. If this triple relation is not of a degenerate species, the sign is related to its object only in consequence of a mental association, and depends upon a habit. Such signs are always abstract and general, because habits are general rules to which the organism has become subjected. They are, for the most part, conventional or arbitrary. They include all general words, the main body of speech, and any mode of conveying a judgment. For the sake of brevity I will call them tokens.

Source: Made in Japan (1986), p. 138.

1950's, On Revolutionary Morality (1958)

Source: Speech to the Conservatives of Manchester (3 April 1872), quoted in William Flavelle Monypenny and George Earle Buckle, The Life of Benjamin Disraeli, Earl of Beaconsfield. Volume II. 1860–1881 (London: John Murray, 1929), p. 531.

The Legend of the Sons of God (1972) as quoted by William Shepherd, "The World of T.C.Lethbridge" (July, 2009)

"Time to Stand Up"
A Devil's Chaplain (2003)
Source: A Devil's Chaplain: Reflections on Hope, Lies, Science, and Love