The marginal value and correlative effective of an opinion not supported by evidence is no more valuable than the second you spent thinking about its value.

"If an opinion contrary to your own makes you angry, that is a sign that you are subconsciously aware of having no good reason for thinking as you do. If someone maintains that two and two are five, or that Iceland is on the equator, you feel pity rather than anger, unless you know so little of arithmetic or geography that his opinion shakes your own contrary conviction. The most savage controversies are those about matters as to which there is no good evidence either way." - Bertrand Russell: On Avoiding Foolish Opinions

via Shane Parrish’s Brain Food newsletter.