Clifford's principle
Clifford's principle holds that it is immoral for individuals, no matter of circumstances, to believe anything without sufficient evidence. While this principle has existed for centuries, it only became prominent in the minds of the common people after the ethics of belief debate in the 19th century between W.K. Clifford and William James, with Clifford articulating the principle in his now-famous work The Ethics of Belief, where he argued in favor of evidentialism.