As we read the letters written to Wormwood, we find Screwtape amazed at how little his nephew knows about tempting. Particularly shocking is an ignorance of the law of undulation and how best to make use of it when attempting to discourage people and encourage them to sin.

The only constant is change. And change is the principle that lies behind the law of undulation.

[people’s] bodies, passions, and imaginations are in continual change, for to be in time means to change. Their nearest approach to constancy, therefore, is undulation – the repeated return to a level from which repeatedly fall back, a series of troughs and peaks.

The word undulation describes a wave-like motion. When this idea is applied to people, as it is by Screwtape, it explains the following phenomenon.

to be in time means to chang

If you had watched your patient carefully you would have seen this undulation in every department of his life – his interest in his work, his affection for his friends, his physical appetites, all go up and down. As long as he lives on earth periods of emotional and bodily richness and liveliness will alternate with periods of numbness and poverty.

Wormwood is reminded that people can be as ignorant of this principle as he is, therefore one of his primary goals is to never let his patient “suspect the law of undulation”.

The challenge for the tempters is, working against this natural flow, to lead a person into thinking that permanence is the normal state of things. Once this is accomplished it works to their advantage in many ways. Continue reading →