Pravity

Doubt not but that sin Will reign among them, as of thee begot; And therefore was law given them, to evince Their natural pravity, by stirring up Sin against law to fight[…].

Source: wiktionary

[…] 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.

Source: wiktionary

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.

Source: wiktionary

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.

Source: wiktionary