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Reasonableness comes in degrees

Watch humanist philosopher Stephen Law explain that some beliefs can be more or less reasonable than others.
I think reasonableness comes in degrees, there’s if you like there’s a sort of scale of reasonableness, let’s make it a vertical scale , and at the top of the scale you have beliefs which are– very reasonable- so my belief that Japan exists seems to me a very reasonable belief and then at the bottom of that scale are beliefs that are very unreasonable, belief in fairies and so on. And then in the middle of the scale, halfway up, maybe belief that there’s maybe extraterrestrial intelligence. It’s not an unreasonable thing to believe but on the other hand it’s by no means established.
So you can see that beliefs can be more or less reasonable; beliefs change their position on this scale of reasonableness over time; beliefs that were once unreasonable are now reasonable and vice versa. I think it’s useful to think of reasonableness in terms of the scale, and I think it’s a particularly useful counter to thinking of the 3-box system of assessing beliefs which you sometimes come across.
The three box system, by which I mean this:
all beliefs have to be sorted into three boxes: those that are proved, those that are disproved, and then in the middle, those that are neither proved nor disproved. Some people like to operate in the three box system, usually in order to mislead folk. First of all, what does ‘proved’ mean? Proved beyond all possible doubt? Well then almost everything goes in the middle box. I mean, I can’t prove beyond all possible doubt that there are no fairies at the bottom of the garden; I’ve got pretty good grounds for thinking that there are no fairies, but proved beyond all possible doubt? No, it’s always just possible that they are there.
Almost everything as I say, if that’s how you understand proved and disproved, Almost all our beliefs get stuck in the same box. But then you’re sticking in there beliefs such as believing in fairies , and believing in electrons, and just putting them on par, as if they’re in the same category, and that is highly misleading. We have now hidden the fact that these beliefs are very very different, in terms of how reasonable they are. So people will use the three box system in order to try and obscure that fact. If ‘proved’ means something else, proved beyond reasonable doubt, now you’re getting lots more beliefs in the proved box and in the disproved box. That’s more helpful.
So there’s an ambiguity as to what ‘proved’ means, but also I think it’s better just to think about how reasonable beliefs are in terms of degree. So use the vertical scale of reasonableness rather than the three box system because if you use the three box system, you lose a lot of information about how relatively reasonable beliefs are.

Stephen Law explains how it is better to think about our beliefs as appearing on a scale of reasonableness, rather than simply thinking of them as proved, unproved, or else all dumped in a box labelled ‘we don’t know either way’.

Just because a belief cannot be proved or disproved beyond all doubt does not mean that it cannot still be reasonably believed, or established beyond reasonable doubt. And just because two different beliefs are neither proved nor disproved, does not mean that one might not be more reasonable than the other.

Sometimes opponents of humanism will attempt to avoid acknowledging that beliefs can have degrees of reasonableness in order to say all beliefs that are neither proved or disproved, however ordinary or extraordinary, are equally justifiable.

Question: What beliefs do you believe should be placed near the top, in the middle, and at the bottom of any scale or reasonableness? What beliefs might have shifted on the scale of reasonableness over time?

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Introducing Humanism: Non-religious Approaches to Life, with Sandi Toksvig

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