As the philosopher Bertrand Russell wrote in a 1928 essay, laypeople must evaluate expert claims by exercising their own careful logic as well. The skepticism that I advocate amounts only to this: (1) that when the experts are agreed, the opposite opinion cannot be held to be certain; (2) that when they are not agreed, no opinion can be regarded as certain by a non-expert; and (3) that when they all hold that no sufficient grounds for a positive opinion exist, the ordinary man would do well to suspend his judgment.
Russell
