You can be good for the mere sake of goodness: you cannot be bad for the mere sake of badness.
 C. S. Lewis, Mere Christianity (1952). copy citation

add
Author C. S. Lewis
Source Mere Christianity
Topic goodness good
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 badness consists in pursuing them by the wrong method, or in the wrong way, or too much. I do not mean, of course, that the people who do this are not desperately wicked. I do mean that wickedness, when you examine it, turns out to be the pursuit of some good in the wrong way. You can be good for the mere sake of goodness: you cannot be bad for the mere sake of badness. You can do a kind action when you are not feeling kind and when it gives you no pleasure, simply because kindness is right; but no one ever did a cruel action simply because cruelty is wrong—only because cruelty was pleasant or useful to him.” source