Dr. R.C. Sproul, noting that the phrase total depravity is not always the most helpful way to summarize what we really mean regarding the impact of sin on humanity, has proposed that we instead use the phrase radical corruption. The advantage of this phrase is twofold. First, the word corruption helps to clarify that the Bible’s doctrine of sin does not mean that people are as evil as they could possibly be. As bad as we are apart from divine grace, we still retain some knowledge of the good and can still do good in an external sense, though not in a way that is fully pleasing to the Lord (Luke 11:11–13). We are not utterly depraved, because we could always act more wickedly than we do. Instead, we are corrupted in every part of our being. Every aspect of ourselves is fallen; nothing has escaped the taint of sin.
The second advantage of the phrase radical corruption is that the word radical captures well the idea that all of our nature has been affected by sin. The English term radical comes from the Latin word radix, which means “root.” To say we are radically corrupted is to say that our sin and fallenness affect not merely the periphery of our natures but get to the very heart of who we are. Sin has not simply made some aspects of our humanity weak; rather, it has infected every constituent aspect of human nature. Since the fall, we are not basically good; we are not mixtures of good and evil in which the good outweighs the bad. Instead, our bent is away from God and the things that please Him. To the extent that we do what is good outwardly, we do it not because we love Him but because we fear punishment and because we want to puff ourselves up with pride.
Perhaps the clearest illustration of our radical corruption is that sin has affected even our minds. Many people believe that although we are now inclined toward sin, our minds have been essentially unaffected by the fall. Apart from grace, we can still reason our way to faith and our thinking is not affected by sin. Of course, we do not deny that fallen people still have the capacity to think logically and to use reason; however, the effects of the fall are such that apart from grace, we will use these powers to reject our Creator. That is what Paul tells us in today’s passage (Rom. 1:21–23). In our radical corruption, we suppress what we know to be true and substitute the worship of idols for the worship of God. This effect of the fall on our minds is what theologians term the “noetic effects of sin.”