Paul also called this dreadful something the Old Adam, and I suppose Darwin would call it the remains of the Wild Beast.

But call it what you will, it is the battle that every well-endowed soul must fight at some point.

And to Ralph it seemed that the final victory of the Evil, the Old Adam, the Flesh, the Wild Beast, the Devil, was certain.

For, was not the pure, unconscious face of Hannah on the Devil's side?
And so the battle had just as well be given up at once, for it must be lost in the end.
But to Ralph, lying there in the still darkness, with his conscience as wide awake as if it were the Day of Doom, there seemed something so terrible in this overflow of the better nature which he knew to be inevitable as soon as the voice of conscience became blunted, that he looked about for help.

He did not at first think of God; but there came into his thoughts the memory of a travel-worn Galilean peasant, hungry, sleepy, weary, tempted, tried, like other men, but having a strange, divine Victory in him by which everything evil was vanquished at his coming.