“When truth and reason cannot be heard, then must presumption rule.”

Letter to Nicolas Gouin Dufief, Philadelphia bookseller (1814) who had been prosecuted for selling the book Sur la Création du Monde, un Systême d'Organisation Primitive by M. de Becourt, which Jefferson himself had purchased.
1810s
Context: I am really mortified to be told that, in the United States of America, a fact like this can become a subject of inquiry, and of criminal inquiry too, as an offence against religion; that a question about the sale of a book can be carried before the civil magistrate. Is this then our freedom of religion? and are we to have a censor whose imprimatur shall say what books may be sold, and what we may buy? And who is thus to dogmatize religious opinions for our citizens? Whose foot is to be the measure to which ours are all to be cut or stretched? Is a priest to be our inquisitor, or shall a layman, simple as ourselves, set up his reason as the rule for what we are to read, and what we must believe? It is an insult to our citizens to question whether they are rational beings or not, and blasphemy against religion to suppose it cannot stand the test of truth and reason.

Maxim 50
Sentences, The Moral Sayings of Publius Syrus, a Roman Slave

2010s, Hard Truths: Law Enforcement (2015)

(Cambridge: 2002), Book 9, Chapter 1, p. 24
On the Trinity (417)

The Myth of Sisyphus (1942), The Absurd Man
Context: Time will prolong time, and life will serve life. In this field that is both limited and bulging with possibilities, everything to himself, except his lucidity, seems unforeseeable to him. What rule, then, could emanate from that unreasonable order? The only truth that might seem instructive to him is not formal: it comes to life and unfolds in men. The absurd mind cannot so much expect ethical rules at the end of its reasoning as, rather, illustrations and the breath of human lives.

Book I, Ch. 3, sec. 4
An Essay Concerning Human Understanding (1689)

Ex parte Hall; In re Wood (1883), L. R. 23 C. D. 653.

In Search of a Better World (1984)
Context: Our aim as scientists is objective truth; more truth, more interesting truth, more intelligible truth. We cannot reasonably aim at certainty. Once we realize that human knowledge is fallible, we realize also that we can never be completely certain that we have not made a mistake.

Source: 1930s- 1950s, The End of Economic Man (1939), p. 84