“why satisfy my own preferences?”
That’s the lynch pin. You don’t have to. You can be utterly incapable of actually following through on what you’ve deemed is a logical behaviour, yet still comment on what is objectively right or wrong. (this goes back to your original comment too)
There are millions of obese people failing to immediately start and follow through on diets and exercise regimes today. This is failing to satisfy their preferences—they have an interest in not dying early, which being obese reliably correlates with. It ostensibly looks like they don’t value health and longevity on the basis of their outward behaviour. This doesn’t make the objectivity of health science any less real. If you do want to avoid premature death and if you do value bodily nourishment, then their approach is wrong. You can absolutely fail to satisfy your own preferences.
Asking the further questions of, “why satisfy my own preferences?”, or “what act in a logically consistent fashion?”, just drift us into the realm of radical scepticism. This is an utterly unhelpful position to hold—you can go nowhere from there. “Why trust my sense data are sometimes veridical?” …you don’t have to, but you’d be mad not to.
Thanks for your remarks.
The is-ought distinction wasn’t discussed explicitly to help include those unfamiliar with Hume. However, the opening section of the essay attempts to establish morality as just another domain of the physical world. There are no moral qualities over and above the ones we can measure, either a) in the consequences of an act, or b) in the behavioural profiles or personality traits in people that reliably lead to certain acts. Both these things are physical (or, at least, material in the latter case), and therefore measurable. Science studies physical reality, and the ambit of morality is a subset of physical reality. Therefore, science studies morality too.
The essay is silent on ‘hedonistic’ utilitarianism (we do not endorse it, either), as again, a) we think these aren’t useful terms with which to structure the debate with as wide an audience as possible, and b) because they are concerns outside the present scope. This essay focuses on establishing the moral domain as just a subset of the physical, and therefore, that there will be moral facts to be obtained scientifically—even if we don’t know how to obtain them just yet. How to perfectly balance competing interests, for example, is for a later discussion. First, convincing people that you actually can do that with any semblance of objectivity is required. The baby needs to walk before it can run.
We discuss cross-cultural claims in the section on everyday empiricism.