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The proverb one might as well be hanged for a sheep as a lamb, and its variants, mean that if the punishment for a minor wrongdoing is to be the same as for a major one, there is no reason for not committing the greater offence.
This proverb alludes to the former penalty for sheep-stealing, which was death by hanging. That penalty was evoked, for example, in the following from a correspondence from Dublin, County Dublin, Ireland, dated Saturday 15th June 1751, published in The Derby Mercury (Derby, Derbyshire, England) of Friday 21st June 1751 [page 3, column 1]:
As many Children have been missed of late, it is feared that the Custom of Kidnapping still continueth […] It is to be hoped that a Bill will be brought into Parliament next Sessions to make this Theft Felony by Law, without Benefit of Clergy, and to jibbet all the Offenders.
A poor Creature in the greatest Distress, whose wretched Family may be starving for want of Food, is oftentimes hanged for stealing a Sheep or a Lamb; and shall a Villain escape who stealeth a Child, who perhaps may be Heir to some Estate and Title, and the only Hope and Comfort of their tender Parents?
—Note: It has been said that, in The rich fool set forth in an exposition on that parable : Luke 12, 16-22 (London: Printed for George Sawbridge, 1662), the English clergyman Nehemiah Rogers (1593-1660) expressed the idea conveyed by the proverb one might as well be hanged for a sheep as a lamb: Nehemiah Rogers supposedly wrote: “As good be hanged for a great deal, as for a little”—but this does not seem to occur in his text (which can be read here).
These are, in chronological order, the earliest occurrences that I have found of the proverb one might as well be hanged for a sheep as a lamb and variants:
1-: From A Collection of English Proverbs Digested into a convenient Method for the speedy finding any one upon occasion; with Short Annotations. Whereunto are added Local Proverbs with their Explications, Old Proverbial Rhythmes, Less known or Exotick Proverbial Sentences, and Scottish Proverbs (Cambridge: Printed by John Hayes, Printer to the University, for W. Morden, 1678), by the English naturalist and theologian John Ray (1627-1705) [Proverbs communicated by Mr Andrew Paschall of Chedsey in Somersetshire, which came not to hand till the copy of this second Edition was delivered to the Bookseller, and so could not be referred to their proper places, page 350]:
As good be hang’d for an old sheep as a young lamb. Somerset.
2-: From Gnomologia: Adagies and Proverbs; Wise Sentences and Witty Sayings, Ancient and Modern, Foreign and British (London: Printed for B. Barker [&c.], 1732), by the British physician Thomas Fuller (1654-1734) [page 25]:
683 As good be hang’d for a Sheep as a Lamb.
3-: From An Account of a Series of Pictures, in the Great Room of the Society of Arts, Manufactures, and Commerce, at the Adelphi (London: Printed for the Author, by William Adlard, 1783), by the Irish painter James Barry (1741-1806) [Sixth Picture. Elizium, or the State of final Retribution, page 157]:
Since, to make use of an antiquated phrase, “a man may as well be hanged for stealing a sheep as a lamb;” and that I have already strayed pretty far from my subject, it may not be amiss to indulge myself a little further, and squeeze into this place a concern of my own.
4-: From The Amorous Jester, Or, The Wit’s Companion; Being a Banquet of Fun, Mirth, Glee and Gallantry; To which is added, Witty Stories, Songs, Poems, Epigrams, Riddles, Toasts, Sentiments, &c. (London: Printed for R. Randall, 1785) [page 25]:
The Parson and the Fowls; or the Maid too cunning for the Master.
A rich old batchelor, a clergyman in the country, having made choice of a pretty young maid to be his house-keeper, had ordered, upon a certain Sunday, a couple of fowls to be got ready for his dinner, that after he had given his congregation a little Christian consolation at church, he might come home and refresh his tired vitals with a dainty modicum […].
[…] Who should take the advantage of the parson’s absence, but his housekeeper’s sweetheart, who, by his pleasant comical hoity toities, and other winning accomplishments, had so wriggled himself into her affections, that it is not unreasonable to think he had as much command as her master.
The maid having mistaken the time of the day, happened to be a little too early with her cookery, so that the fowls were full ready before the parson had given his hungry auditory leave to return home to their puddings and dumplings. The sweetheart being a fellow of an incomparable stomach, thought it a great pity, such good victuals should be spoiled for want of eating, and very eagerly solicited his loving Jug to spare him one of the fowls to stop a little hole he had in his appetite, telling her one would be sufficient for her master, and that she had wit enough to contrive some story or other, handsomely to excuse the matter, and blind him from the true knowledge of what became of it.
The maid being willing to oblige her lover, who she found was so desirous to oblige her upon all occasions, ventured to take up one to save the longing of her sweetheart, who being very well prepared for such a nice entertainment, gobbled it up with such expedition, that before his benefactress had wound up the jack, he had not so much as left the claws, which the poor cockral used to scratch the dunghill withal.
He had no sooner dispatched his sweetheart’s first courtesy, but he began to be very importunate with her for the second, telling her an excuse was as easy made for both as for one, and that she had as good be hanged for a sheep as a lamb; till at last, by adding a few melting kisses to his ravenous solicitation, he prevailed upon her to draw the other off the spit, that he might finish his meal by robbing the parson of his Sunday’s dinner.
5-: From A Year’s Journey through the Pais Bas; Or, Austrian Netherlands (London: Printed for J. Debrett, 1786), by the British-Army officer and author Philip Thicknesse (1719-1792) [Letter XXIX, page 241]:
Having now made you a receiver of stolen goods, and equally criminal with the thief, I will own to you, that I thought I might as well suffer for a sheep as a lamb, and therefore stole another.
