A man knows, on perfectly good evidence, that a pretty girl of his acquaintance is a liar and cannot keep a secret and ought not to be trusted
 C. S. Lewis, Mere Christianity (1952). copy citation

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Author C. S. Lewis
Source Mere Christianity
Topic trust evidence
Date 1952
Language English
Reference
Note Adapted from a series of BBC radio talks made between 1942 and 1944
Weblink https://www.dacc.edu/assets/pdfs/PCM/merechristianitylewis.pdf

Context

“on the contrary, my faith is based on reason. It is my imagination and emotions. The battle is between faith and reason on one side and emotion and imagination on the other. When you think of it you will see lots of instances of this. A man knows, on perfectly good evidence, that a pretty girl of his acquaintance is a liar and cannot keep a secret and ought not to be trusted: but when he finds himself with her his mind loses its faith in that bit of knowledge and he starts thinking, ‘Perhaps she’ll be different this time,’ and once more makes a fool of himself and tells her something he ought not to have told her.” source