Definition of "pravity"

Doubt not but that sinWill reign among them, as of thee begot;And therefore was law given them, to evinceTheir natural pravity, by stirring upSin against law to fight […] .

1667, John Milton, Paradise Lost‎

[…] they alledged, That becauſe I had ſome Rudiments of Reaſon, added to the natural pravity of thoſe Animals, it was to be feared, I might be able to ſeduce them into the woody and mountainous parts of the Country, and bring them in Troops by night to deſtroy the Houyhnhnms Cattle, as being naturally of the ravenous kind, and averſe from Labour.

1726 October 28, [Jonathan Swift], “The Author’s Oeconomy and Happy Life among the Houyhnhnms. […]”, in Travels into Several Remote Nations of the World. […] [Gulliver’s Travels], volume II, London: […] Benj[amin] Motte, […], part IV (A Voyage to the Houyhnhnms), page 308

In some parishes the Lord's Prayer is suffered: in others it is still rejected as a form; and he that should make it part of his supplication would be suspected of heretical pravity.

1775, Samuel Johnson, “Ostig In Sky”, in A Journey to the Western Islands of Scotland‎

Still, it is possible, that a man's conscience may be so obdurate, as not to perceive the pravity of mendacity, when exercised for his supposed benefit, while he yet retains a regard for truth when engaged in relating his exploits to others.

1831, Various, The American Quarterly Review, No. 17, March 1831‎