I agree this form of argument is very unconvincing. That “people don’t act as if Y is true” is a pretty rubbish defeater for “people believe Y is true”, and a very rubbish defeater for “X being true” simpliciter. But this argument isn’t Ord’s, but one of your own creation.
Again, the validity of the philosophical argument doesn’t depend on how sincerely a belief is commonly held (or whether anyone believes it at all). The form is simply modus tollens:
If X (~sanctity of life from conception) then Y (natural embryo loss is—e.g. a much greater moral priority than HIV)
¬Y (Natural embryo loss is not a much greater moral priority than (e.g.) HIV)
¬X (The sanctity of life from conception view is false)
Crucially, ¬Y is not motivated by interpreting supposed revealed preferences from behaviour. Besides it being ~irrelevant (“Person or group does not (really?) believe Y -->?? Y is false”) this apparent hypocrisy can be explained by ignorance rather than insincerity: it’s not like statistics around natural embryo loss are common knowledge, so their inaction towards the Scourge could be owed to them being unaware of it.
¬Y is mainly motivated by appeals to Y’s apparent absurdity. Ord (correctly) anticipates very few people on reflection would find Y plausible, and so would find if X indeed entailed Y, this would be a reason to doubt X. Again, it is the implausibility on rational reflection, not the concordance of practice to those who claim to believe it, which drives the argument .
I agree this form of argument is very unconvincing. That “people don’t act as if Y is true” is a pretty rubbish defeater for “people believe Y is true”, and a very rubbish defeater for “X being true” simpliciter. But this argument isn’t Ord’s, but one of your own creation.
Again, the validity of the philosophical argument doesn’t depend on how sincerely a belief is commonly held (or whether anyone believes it at all). The form is simply modus tollens:
If X (~sanctity of life from conception) then Y (natural embryo loss is—e.g. a much greater moral priority than HIV)
¬Y (Natural embryo loss is not a much greater moral priority than (e.g.) HIV)
¬X (The sanctity of life from conception view is false)
Crucially, ¬Y is not motivated by interpreting supposed revealed preferences from behaviour. Besides it being ~irrelevant (“Person or group does not (really?) believe Y -->?? Y is false”) this apparent hypocrisy can be explained by ignorance rather than insincerity: it’s not like statistics around natural embryo loss are common knowledge, so their inaction towards the Scourge could be owed to them being unaware of it.
¬Y is mainly motivated by appeals to Y’s apparent absurdity. Ord (correctly) anticipates very few people on reflection would find Y plausible, and so would find if X indeed entailed Y, this would be a reason to doubt X. Again, it is the implausibility on rational reflection, not the concordance of practice to those who claim to believe it, which drives the argument .