Each man is at every moment subjected to several different sets of law but there is only one of these which he is free to disobey. As a body, he is subjected to gravitation and cannot disobey it; if you leave him unsupported in mid-air, he has no more choice about falling than a stone has.
 C. S. Lewis, Mere Christianity (1952). copy citation

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Author C. S. Lewis
Source Mere Christianity
Topic choice law
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

“The idea was that, just as all bodies are governed by the law of gravitation, and organisms by biological laws, so the creature called man also had his law—with this great difference, that a body could not choose whether it obeyed the law of gravitation or not, but a man could choose either to obey the Law of Human Nature or to disobey it. We may put this in another way. Each man is at every moment subjected to several different sets of law but there is only one of these which he is free to disobey. As a body, he is subjected to gravitation and cannot disobey it; if you leave him unsupported in mid-air, he has no more choice about falling than a stone has. As an organism, he is subjected to various biological laws which he cannot disobey any more than an animal can. That is, he cannot disobey those laws which he shares with other things; but the law which is peculiar to his human nature, the law he does not share with animals or vegetables or inorganic things, is the one he can disobey if he chooses.” source