The Reformed doctrine of man’s total depravity effectively denies the possibility of anyone acting with integrity because in the first place (they say) nothing we do is so truly good as to be free of the taint of sin, and in the second place everyone sins, and in the third place even the mildest of sins is worthy of infinite punishment. How then can there be anyone who acts with genuine integrity? The notion implies that this is a consistent, habitual aspect of such a man’s character, but that’s precisely the sort of thing that is ruled out by total depravity.
It is not ruled out by the Bible, however.
You guide those who act with integrity and keep your ways in mind (Isaiah 64:4a, JB).
Those who insist upon the idea of man’s total depravity have difficulties with passages like this, but this verse and others similar to it are perfectly consistent with the Catholic Faith. We are (with God’s help) able to act with integrity and to keep His ways in mind. We are not incapable of habitual integrity; we are not enslaved by sin to such a degree that we cannot do any good at all. It is true that we cannot save ourselves, but the Church has never suggested that we can do so.
If the Reformed were correct, then it seems that consistency would require them to deny that anyone acts with integrity. Their appeal to Romans 3 in defense of their view does not leave them much wiggle room for saying otherwise. But if no one acts with integrity, then Isaiah’s declaration is reduced to mere rhetoric; he would be saying it about nobody at all because nobody would fit the definition.