“I really have no claim to rank myself among fatalistic, materialistic, or atheistic philosophers. Not among fatalists, for I take the conception of necessity to have a logical, and not a physical foundation; not among materialists, for I am utterly incapable of conceiving the existence of matter if there is no mind in which to picture that existence; not among atheists, for the problem of the ultimate cause of existence is one which seems to me to be hopelessly out of reach of my poor powers. Of all the senseless babble I have ever had occasion to read, the demonstrations of these philosophers who undertake to tell us all about the nature of God would be the worst, if they were not surpassed by the still greater absurdities of the philosophers who try to prove that there is no God.”

Letter to Edward Newenham (20 October 1792) http://etext.lib.virginia.edu/etcbin/toccer-new2?id=WasFi32.xml&images=images/modeng&data=/texts/english/modeng/parsed&tag=public&part=155&division=div1, these statements and one from a previous letter to Newenham seem to have become combined and altered into a misquotation of Washington's original statements to read:
1790s
Context: Of all the animosities which have existed among mankind, those which are caused by difference of sentiments in religion appear to be the most inveterate and distressing, and ought most to be deprecated. I was in hopes that the enlightened and liberal policy, which has marked the present age, would at least have reconciled Christians of every denomination so far that we should never again see the religious disputes carried to such a pitch as to endanger the peace of society.

Character, of Witness Lee - By Living Stream Ministry, ISBN 978-0-87083-322-9

Source: 1840s, The Mathematical Analysis of Logic, 1847, p. iii
Context: That to the existing forms of Analysis a quantitative interpretation is assigned, is the result of the circumstances by which those forms were determined, and is not to be construed into a universal condition of Analysis. It is upon the foundation of this general principle, that I purpose to establish the Calculus of Logic, and that I claim for it a place among the acknowledged forms of Mathematical Analysis, regardless that in its object and in its instruments it must at present stand alone.

Kindle location 7549, emphasis in original.
The Blank Slate (2002)

Letter of Constantine to the Antiochians (332)
Constantine the Great : Letters
Context: How pleasing to the wise and intelligent portion of mankind is the concord which exists among you! And I myself, brethren, am disposed to love you with an enduring affection, inspired both by religion, and by your own manner of life and zeal on my behalf. It is by the exercise of right understanding and sound discretion, that we are enabled really to enjoy our blessings... Indeed, amongst brethren, whom the selfsame disposition to walk in the ways of truth and righteousness promises, through the favor of God, to register among his pure and holy family, what can be more honorable than gladly to acquiesce in the prosperity of all men?... O holy faith, who givest us in our Saviour's words and precepts a model, as it were, of what our life should be, how hardly wouldst thou thyself resist the sins of men, were it not that thou refusest to subserve the purposes of gain! In my own judgment, he whose first object is the maintenance of peace, seems to be superior to Victory herself; and where a right and honorable course lies open to one's choice, surely no one would hesitate to adopt it. I ask then, brethren, why do we so decide as to inflict an injury on others by our choice? Why do we covet those objects which will destroy the credit of our own reputation?... Lastly, in accordance with your usual sound judgment, do ye exhibit a becoming diligence in selecting the person of whom you stand in need, carefully avoiding all factious and tumultuous clamor; for such clamor is always wrong, and from the collision of discordant elements both sparks and flame will arise. I protest, as I desire to please God and you, and to enjoy a happiness commensurate with your kind wishes, that I love you, and the quiet haven of your gentleness, now that you have cast from you that which defiled, and received in its place at once sound morality and concord, firmly planting in the vessel the sacred standard, and guided, as one may say, by a helm of iron in your course onward to the light of heaven.

Letter http://www.darwinproject.ac.uk/letter/entry-12041 to John Fordyce, 7 May 1879
Other letters, notebooks, journal articles, recollected statements

Speech https://api.parliament.uk/historic-hansard/commons/1861/apr/15/first-night#column_595 in the House of Commons (15 April 1861)
1860s

Source: "The Masters of Suspicion", p. 84

Source: Why I Am a Vegetarian: An Address Delivered before the Chicago Vegetarian Society (1895), pp. 11—12