Russell Blackford has written a good blog post summarising the philosophically-minded objections to Sam Harris's is-ought pseudo-dismissal. I'm basically in agreement with Harris, although note the (valid) objections of a number of philos about the meta-ethics - I just don't think they matter *that* much! But Russell makes a good point when he summarises Harris's argument comparing his putative moral science to medical science:
Unfortunately, we are nowhere near to having the sort of general agreement as to the goals of, well, moralising, if you will, that we do with practising medicine or science. So it's no use arguing:I think this is right, at a foundational level. However, Russell agrees that applying ethics is something that can be done:
P1. The ultimate goals of medicine and science are contestable
P2. We can practice medicine and science with no terrible difficulty.
C. We can, with no terrible difficulty, practice anything whose ultimate goals are contestable.
Hence, we can, with no terrible difficulty, practice a "science of morality".
The correct conclusion, at "C.", is that we can, with no terrible difficulty, practice some things whose ultimate goals are contestable. As far as this argument goes, whether morality is one of those things is left as an open question. It really depends on just how much debate there is about a practice's ultimate goals, and how this pans out in practice. Unfortunately, the ultimate goals of morality are so controversial, and so disputed at such a deep level, that it's not surprising when much of what goes on in moral philosophy relates to trying to get agreement on the ultimate goals.
But Harris doesn't actually need to make an unheralded breakthrough in metaethics to establish his main point about the possibility and desirability of criticising moral systems. If those moral systems are harmful to human wellbeing ... then criticise them for it! I think hammers exist to drive nails and that it's approximately correct to say that moral systems exist to conduce to human wellbeing and, to some extent, the wellbeing of other sentient creatures.And of course each society establishes a way of living that announces their conception of the best morality - it would be disingenuous to suggest otherwise.
The meta-ethical problems arise, it seems to me, from the inscrutable origins of our morality. Because we have evolved in the environment according to events that are impossible to retrodict, let alone predict, we find it very difficult to determine the cause of every animal's every trait. The morality we have (signs of which appear in other mammals) has been a necessary development for our survival, or is a consequence of another feature that was necessary for our survival. But it's still just a *feeling*, so consequently isn't an *infallible* guide to what is right for us. It's not a bad starting point, but because many think they have nothing else to go on, they trust their 'gut' feeling over all else.
The religious turn morality's *fallibility* (observed empirically) and turn it into *arbitrariness*. To bolster their flagging confidence in 'what is right', they invest a God with good and call it absolute and objective. Much analysis down the years has yet to show that this approach is tenable or, indeed, plausible. One would think that a good-invested God might have an effect substantially different from an evil-invested God, but it's difficult to see how either could result in the universe we have.
The rationalist can accept that we have a sense of what is good without it being absolute, so tempers it with a good dose of reason and evidence; like everything else in life.