Few confusions are more common, or more perplexing, today than the confusion between two quite different uses of the word ‘natural’; yet both uses are valid enough if rightly understood; and the distinction between them is a very simple one.

On the one hand, we are always saying, or hearing it said, that this or that action, though not commendable, is ‘natural enough’ or ‘only natural’. It is only natural for people to lose their tempers or their heads sometimes, only natural if occasionally they oversleep or overeat, only natural if sometimes they let this or that passion get the better of them. What does the phrase mean? It means, in effect, ‘only to be expected’. And why is it to be expected? Because that, to use another common phrase, is ‘only human nature’ as we know it. But what is the human nature that we know in everyday experience? It is, in the language of Catholic theology, fallen human nature.

Fallen human nature means human nature, not as it was created by God, not as it was intended to be by God, but as it exists now, warped and twisted by evil. It is not wholly evil, far from it; but the evil tendencies are there, as we all know from our own experience; in our better moments we realize that we ought to be conquering them, integrating the energies which find an outlet in evil actions into the organic unity of the good life; but again and again we fail, or we forget altogether even to try, and then nature-as-we-know-it has its way.