When Calvinists use the phrase total depravity…

When Calvinists use the phrase total depravity, this is what they mean: not that humans are hopelessly evil but rather that every aspect of human nature has been affected by the Fall, including our intellectual life—and thus every aspect needs to be redeemed. Nothing was left pristine and innocent.

Nancy Pearcey, from Total Truth, kindle location 2090

However much fallen and perverted…

In reading profane authors, the admirable light of truth displayed in them should remind us, that the human mind, however much fallen and perverted from its original integrity, is still adorned and invested with admirable gifts from its Creator…. Their example should teach us how many gifts the Lord has left in possession of human nature, notwithstanding of its having been despoiled of the true good.

John Calvin, quoted in Is the Bible Sufficient?—Solid Ground, May-June, 2007 by Greg Koukl, p. 3

In a state of rebellion…

In a state of rebellion, individuals suffer from a totally depraved nature that keeps them alienated from a holy and just God. This depravity, while not making man completely evil, nevertheless corrupts his entire being including his mind, will, body, and spirit. But to what extent does this condition affect the imago Dei? Did sin completely erase God’s image from humankind?

Kenneth Richard Samples, from A World of Difference, kindle location 1961

Sin cannot destroy man’s rationality…

Sin cannot destroy man’s rationality altogether, for then he would no longer be capable of sin.

Thomas Aquinas, quoted in Encyclopedia of Christian Apologetics, by Norman Geisler, under the topic ‘Noetic Effects of Sin’