From The Screwtape Letters—a fictional work written from a senior demon’s perspective, advising a junior tempter.

When once a sort of official, legal, or nominal Unselfishness has been established as a rule-a rule for the keeping of which their emotional resources have died away and their spiritual resources have not yet grown-the most delightful results follow. In discussing any joint action, it becomes obligatory that A should argue in favour of B’s supposed wishes and against his own, while B does the oppos-ite. It is often impossible to find out either party’s real wishes; with luck, they end by doing something that neither wants, while each feels a glow of self-righteousness and harbours a secret claim to preferential treatment for the unselfishness shown and a secret grudge against the other for the ease with which the sacrifice has been accepted.

The Screwtape Letters
C. S. Lewis