In Book 3, Chapter 58 of The Imitation of Christ, the idea of nature and grace is explored extensively.
Fr. Robert Nixon says, “This is something which people who’ve studied theology will perhaps have thought about quite a lot, but other people maybe not so much. So the idea of this contrast or these two fortunes of nature and grace. So we do certain things by nature. It’s within who we are, our created being, but we do things also by grace, which is something which comes from God above.
“Now, in talking about nature and grace, it’s important not to make too hard a distinction between the two because in fact our nature comes from God as well. So it actually is a form of grace. So sometimes nature and grace are in opposition, but at the same time, we don’t want to draw too strongly a dichotomy between them, which is what the Protestant traditions tend to do, making nature and grace in firm opposition, which of course is not the reality because God has given us our nature in order that we may glorify him.”
Episode 14 of The Commentaries dives into Book Three of The Imitation of Christ, chapters 54-59.