Russell writes: “The essence of the Liberal outlook lies not in what opinions are held, but in how they are held: instead of being held dogmatically, they are held tentatively, and with a consciousness that new evidence may at any moment lead to their abandonment.” (Unpopular Essays, 1950, Ch.1 “Philosophy and Politics”, p.15)
Is he right? Shouldn’t a liberal outlook uphold the right to life, or the right to a fair trial, dogmatically? True, Russell says “opinions” rather than “principles”. That only kicks the problem upstairs, in discerning opinions from principles. Shouldn’t the principles we endorse agree with our best-grounded opinions, the ones that constitute our knowledge and understanding of social life? How could we bank on principles “with a consciousness that new evidence may at any moment lead to their abandonment”? What would that say about our stability as agents and reasoners? Contrariwise, is moderation in adjusting to evidence rational, or does the lag it presupposes mire us into effectively not being sensitive enough to the evidence in question?
We often have to make reasoned decisions in conditions of uncertainty. Some of our uncertainty may concern not only the circumstances, but also how much faith we should put in the principles we use. Clearly we should be sensitive to evidence, new and old, and should try to make the best use of it we can. But how to spell out sensitivity to evidence so that the principles it bears on can still work for a while as they are either boosted or undermined is, I think, tricky. This raises (among many others) engineering questions (how weak a principle can still work?), ethical questions (isn’t it unjust to let weakened principles operate even for a while?) and epistemological ones (if a balance is to be reached, who is to say when it has been reached?) It’s hard to be interested in how epistemology and ethics connect and not be troubled by what Russell says.