Full Idea
If I desire to get rid of my flu symptoms, and believe the only way to do it is death, I am committed to desiring my death. …there is no plausible logic of practical reason.
Gist of Idea
We don't accept practical reasoning if the conclusion is unpalatable
Source
John Searle (Rationality in Action [2001], Ch.8.II)
Book Reference
Searle,John R.: 'Rationality in Action' [MIT 2001], p.245