“A Judge must bear in mind that when he tries a case he is himself on trial.”

Speaking Out (2006)

Source: The Moral Judgment of the Child (1932), Ch. 2 : Adult Constraint and Moral Realism <!-- p. 133 -->
Context: It is when the child is accustomed to act from the point of view of those around him, when he tries to please rather than to obey, that he will judge in terms of intentions. So that taking intentions into account presupposes cooperation and mutual respect. Only those who have children of their own know how difficult it is to put this into practice. Such is the prestige of parents in the eyes of the very young child, that even if they lay down nothing in the form of general duties, their wishes act as law and thus give rise automatically to moral realism (independently, of course, of the manner in which the child eventually carries out these desires). In order to remove all traces of moral realism, one must place oneself on the child's own level, and give him a feeling of equality by laying stress on one's own obligations and one's own deficiencies. In this way the child will find himself in the presence, not of a system of commands requiring ritualistic and external obedience, but of a system of social relations such that everyone does his best to obey the same obligations, and does so out of mutual respect. The passage from obedience to cooperation thus marks a progress analogous to that of which we saw the effects in the evolution of the game of marbles: only in the final stage does the morality of intention triumph over the morality of objective responsibility.
When parents do not trouble about such considerations as these, when they issue contradictory commands and are inconsistent in the punishments they inflict, then, obviously, it is not because of moral constraint but in spite of and as a reaction against it that the concern with intentions develops in the child. Here is a child, who, in his desire to please, happens to break something and is snubbed for his pains, or who in general sees his actions judged otherwise than he judges them himself. It is obvious that after more or less brief periods of submission, during which he accepts every verdict, even those that are wrong, he will begin to feel the injustice of it all. Such situations can lead to revolt. But if, on the contrary, the child finds in his brothers and sisters or in his playmates a form of society which develops his desire for cooperation and mutual sympathy, then a new type of morality will be created in him, a morality of reciprocity and not of obedience. This is the true morality of intention and of subjective responsibility. <!--
In short, whether parents succeed in embodying it in family life or whether it takes root in spite of and in opposition to them, it is always cooperation that gives intention precedence over literalism, just as it was unilateral respect that inevitably provoked moral realism. Actually, of course, there are innumerable intermediate stages between these two attitudes of obedience and collaboration, but it is useful for the purposes of analysis to emphasize the real opposition that exists between them.

Principles of Legislation (1830), Ch. X : Analysis of Political Good and Evil; How they are spread in society
Context: It is with government, as with medicine. They have both but a choice of evils. Every law is an evil, for every law is an infraction of liberty: And I repeat that government has but a choice of evils: In making this choice, what ought to be the object of the legislator? He ought to assure himself of two things; 1st, that in every case, the incidents which he tries to prevent are really evils; and 2ndly, that if evils, they are greater than those which he employs to prevent them.
There are then two things to be regarded; the evil of the offence and the evil of the law; the evil of the malady and the evil of the remedy.
An evil comes rarely alone. A lot of evil cannot well fall upon an individual without spreading itself about him, as about a common centre. In the course of its progress we see it take different shapes: we see evil of one kind issue from evil of another kind; evil proceed from good and good from evil. All these changes, it is important to know and to distinguish; in this, in fact, consists the essence of legislation.

Variant: The moment people come to know love, they run the risk of carrying hate.

Source: Winnie-the-Pooh

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 59.

L'homme qui peut empreindre perpétuellement la pensée dans le fait est un homme de génie; mais l'homme qui a le plus de génie ne le déploie pas à tous les instants, il ressemblerait trop à Dieu.
Source: A Daughter of Eve (1839), Ch. 3: The Story of a Happy Woman.

Book IV, Chapter II, 91; translation by H. E. Butler
Compare: "Liars ought to have good memories", Algernon Sidney, Discourses on Government, chapter ii, section xv.
Alternate translation for "solent excidere quae falsa sunt": False things tend to be forgotten
De Institutione Oratoria (c. 95 AD)