[Nocturne]

jposemen,

I think that you are correct to interpret Carl Sagan's comment that 'extraordinary claims require extraordinary evidence' as proposal for the adoption of a convention i.e. an ethical proposal. It is quite clear that someone can make a claim and believe it without any evidence whatever, and even despite contradictory evidence. Moreover, it is quite clear that the presence or absence of evidence does not make a claim true or false, since a true statement is true regardless of what evidence we have accumulated i.e. the truth or falsity of a claim is an objective property which stands independent of anything we do.

Therefore, I think the claim is best read as the ethical proposal that we ought not to believe a claim which seems to us to be extraordinary unless we have some extraordinary evidence to justify that belief. I, for one, do not agree with this proposal. I am primarily concerned with whether the claims which people make are true or false, and not whether they ought to believe them or not. In fact, I am somewhat disgusted with those who seem to be inappropriately concerned with what others are permitted to believe according to the evidence, and I find it a distraction from the far more interesting issue of whether the claims being made are true or false.