For the advancement of science and protection of the right to freedom of expression, Bertrand Russell advocated that one should always remember:
None of our beliefs are quite true; all have at least a penumbra of vagueness and error. The methods of increasing the degree of truth in our beliefs are well known; they consist in:
- Hearing all sides
- Trying to ascertain all the relevant facts
- Controlling our own bias by discussion with people who have the opposite bias
- Cultivating a readiness to discard any hypothesis which has proved inadequate
These methods are practised in science, and have built up the body of scientific knowledge. Every man of science whose outlook is truly scientific is ready to admit that what passes for scientific knowledge at the moment is sure to require correction with the progress of discovery.
Nevertheless, it is near enough to the truth to serve for most practical purposes, though not for all. In science, where alone something approximating to genuine knowledge is to be found, men’s attitude is tentative and full of doubt.