The salmon swimming upstream to spawn may be wily in a hundred ways, but she cannot even contemplate the prospect of abandoning her reproductive proj… - Daniel Dennett

From what can "ought" be derived. The most compelling answer is this: ethics must be somehow based on an appreciation of human nature — on a sense of what a human being is or might be, and on what a human being might want to have or want to be. If that is naturalism, then naturalism is no fallacy. No one could seriously deny that ethics is responsive to such facts about human nature. We may just disagree about where to look for the most compelling facts about human nature -n novels, in religious texts, in psychological experiments, in biological or anthropological investigations. The fallacy is not naturalism but, rather, any simple-minded attempt to rush from facts to values. In other words, the fallacy is greedy reductionism of values to facts, rather than reductionism considered more circumspectly, as the attempt to unify our world-view so that out ethical principles don't clash irrationally with the way the world is.

[W]hat good to us is the gods' knowledge if we can't get it from them? How could one communicate with the gods? Our ancestors (while they were alive!) stumbled on an extremely ingenious solution: divination. We all know how hard it is to make the major decisions of life: should I hang tough or admit my transgression, should I move or stay in my present position, should I go to war or not, should I follow my heart or my head? We still haven't figured out any satisfactory systematic way of deciding these things. Anything that can relieve the burden of figuring out how to make these hard calls is bound to be an attractive idea. Consider flipping a coin, for instance. Why do we do it? To take away the burden of having to find a reason for choosing A over B. We like to have reasons for what we do, but sometimes nothing sufficiently persuasive comes to mind, and we recognize that we have to decide soon, so we concoct a little gadget, an external thing that will make the decision for us. But if the decision is about something momentous, like whether to go to war, or marry, or confess, anything like flipping a coin would be just too, well, flippant. In such a case, choosing for no good reason would be too obviously a sign of incompetence, and, besides, if the decision is really that important, once the coin has landed you'll have to confront the further choice: should you honor your just-avowed commitment to be bound by the flip of the coin, or should you reconsider? Faced with such quandaries, we recognize the need for some treatment stronger than a coin flip. Something more ceremonial, more impressive, like divination, which not only tells you what to do, but gives you a reason (if you squint just right and use your imagination). Scholars have uncovered a comically variegated profusion of ancient ways of delegating important decisions to uncontrollable externalities. Instead of flipping a coin, you can flip arrows (belomancy) or rods (rhabdomancy) or bones or cards (sortilege), and instead of looking at tea leaves (tasseography), you can examine the livers of sacrificed animals (hepatoscopy) or other entrails (haruspicy) or melted wax poured into water (ceroscopy). Then there is moleosophy (divination by blemishes), myomancy (divination by rodent behavior), nephomancy (divination by clouds), and of course the old favorites, numerology and astrology, among dozens of others.

Of all the mind tools we acquire in the course of furnishing our brains from the stockpiles of culture, none are more important, of course, than words — first spoken, then written. Words make us more intelligent by making cognition easier, in the same way (many times multiplied) that beacons and landmarks make navigation in the world easier for simple creatures. Navigation in the abstract multidimensional world of ideas is simply impossible without a huge stock of movable, memorable landmarks that can be shared, criticized, recorded, and looked at from different perspectives.