I think psychologist Tom Gilovich is the original source of the “Can I?” vs. “Must I?” description of motivated reasoning. He wrote about it in his 1991 book How We Know What Isn’t So.
For desired conclusions, we ask ourselves, “Can I believe this?”, but for unpalatable conclusions we ask, “Must I believe this?
I think psychologist Tom Gilovich is the original source of the “Can I?” vs. “Must I?” description of motivated reasoning. He wrote about it in his 1991 book How We Know What Isn’t So.