“Why, Sir, it is difficult to settle the proportion of iniquity between them.”

Preface of M. Quetelet
A Treatise on Man and the Development of His Faculties (1842)

Colonel Claud Runciman, Captain Richard Sharpe, and Sergeant Patrick Harper, p. 331
Sharpe (Novel Series), Sharpe's Battle (1995)

Er ist eine Skala der Proportionen, die das Schlechte schwierig und das Gute leicht macht.
On the Modulor. Letter sent to Le Corbusier (1946); quoted in Modulor (1953)
1940s

July 14, 1763, p. 123
Life of Samuel Johnson (1791), Vol I

Faraday's purported reply to William Gladstone, then British Chancellor of the Exchequer (minister of finance), when asked of the practical value of electricity (1850) as quoted in Democracy and Liberty (1899) by William Edward Hartpole Lecky, p. xxxi , and in Discovery Or The Spirit And Service Of Science (1918) by R.A Gregory, p 3. The variant "One day sir, you may tax it." is given in The Harvest of a Quiet Eye : A Selection of Scientific Quotations (1977), p. 56, but they source it to Discovery which differs in its quote. According to Snopes in "Long Ago and Faraday" http://www.snopes.com/quotes/faraday.asp, it is most likely an invented quotation, as there are no contemporaneous records, though Lecky did live through the same time as Faraday and Gladstone.
Disputed

Letter to James Macpherson, 20 June 1778. (Quotation used as epigram to Władysław Tatarkiewicz, "Dwa pojęcia poezji" ("Two Concepts of Poetry"), in Tatarkiewicz's book, Parerga, Warsaw, Państwowe Wydawnictwo Naukowe, 1978, pp. 20–38.)
Letters to and from Dr. Samuel Johnson

Reply to Colonel Barnard E. Bee when he reported that the enemy were beating them back. At the First Battle of Bull Run (21 July 1861); as quoted in Stonewall Jackson As Military Commander (2000) by John Selby, p. 21

No. 163 (8 October 1751)
The Rambler (1750–1752)
Context: Every man is rich or poor according to the proportion between his desires and his enjoyments; any enlargement of wishes is therefore equally destructive to happiness with the diminution of possession, and he that teaches another to long for what he never shall obtain is no less an enemy to his quiet than if he had robbed him of part of his patrimony.

Draft for a Statement of Human Obligation (1943)
Context: The proportions of good and evil in any society depend partly upon the proportion of consent to that of refusal and partly upon the distribution of power between those who consent and those who refuse.
If any power of any kind is in the hands of a man who has not given total, sincere, and enlightened consent to this obligation such power is misplaced.
If a man has willfully refused to consent, then it is in itself a criminal activity for him to exercise any function, major or minor, public or private, which gives him control over people's lives. All those who, with knowledge of his mind, have acquiesced in his exercise of the function are accessories to the crime.
Any State whose whole official doctrine constitutes an incitement to this crime is itself wholly criminal. It can retain no trace of legitimacy.
Any State whose official doctrine is not primarily directed against this crime in all its forms is lacking in full legitimacy.
Any legal system which contains no provisions against this crime is without the essence of legality. Any legal system which provides against some forms of this crime but not others is without the full character of legality.
Any government whose members commit this crime, or authorize it in their subordinates, has betrayed its function.