I think those who believe in an objective morality make their choices the same way as those who do not. I just think they are mistaken about the existence of objective moral truths (except in the sense of being something that society agrees on – but that is different from how I am using the term, to mean having an abstract existence separate from human culture and society).

In the end, there are many moral choices that are quite obviously optimal, regardless of your source of reasoning. But if someone bases their moral judgments on what it says in a sacred text, then I would say that is unreasonable, especially as many of the proscriptions within such texts do not appear to be particularly moral to most people now.

That does not mean we are a slave to our evolutionarily-programmed imperatives and that all apparently moral choices are simply the expression of those subconscious constraints (like, “care for your young” or “don’t do things that will get you socially ostracised”). The cerebral cortex allows us to transcend the drives of evolution. Because we have the capacity for abstract thought, we can think about morality at a remove from biological drives and consider whether we can come up with societal rules that might be better – i.e., improve the well-being of more people – than the ones we come programmed with. Even if we do that, however, these will still be pragmatically derived rules or guidelines based on our consideration of the factors that will best enhance fairness, societal stability, prosperity, etc.

None of those will be a “truth” waiting to be discovered. The problem with that idea is that you then have to say where they come from – if it’s from a God, then you are left with the problem posed by Socrates: “Are things good because God says they are?” (That seems a bit open to the whims and caprices of the deity, especially if you look at some of the rather bizarre proscriptions associated with various religions). “Or does God say they are good because they ARE good?” If so, that still leaves the question of how they are defined as good.

Morality is about making optimal choices, taking many different parameters into consideration, not about discovering the “fact” of which choice is correct. Your analogy with discerning truth from falsehood (I presume in others’ statements) thus breaks down because in that case there is a truth to be discerned.

“Love thy neighbor as thy self” came to mind while reading this sentence: “Moral behaviour arose in humans as an extension of the biological systems involved in recognition and care of mates and offspring.”

Also, concerning the “universality” of (certain) moral values: the ideal of an international order based on reason and justice in place of force and fraud makes sense in the nuclear age, a matter of collective, enlightened self-interest. Or at least it could be seen that way. The Hebraic idea of God was originally conceived in those terms (minus nuclear weapons, but as a matter of enlightened self-interest) at least by my close reading of the Patriarchal narratives in Genesis (not the Mosaic period later). The early Hebrews were a small, weak trading people who depended on their reputation for honesty and fair-dealing to survive in a matrix of powerful city-states among whom they lived and moved and “had their being.”

The idea of a just God who would protect the weak was later taken up by the masses of ordinary peasants and craftsmen as a matter of (perhaps unenlightened) self-interest. At least this is a possible reading.

But again, that was a great piece of synthesis.

Similarly, I would think that the ‘moral’ problems we face are similar from culture to culture. Betrayal of friends and relatives is the same in any culture. It would seem to me that the differences will be along the lines of differences between groups that have spent a longer time under selection for very large and complex societies (eg, China over the last 4,000 years) and those that have spent much of those same 4,000 years in small-scale cultures, as well as between males and females, where the problems have, until very recently, been very different, it seems to me. However, I would expect that the base ‘moral’ hardware is the same among all human groups with some groups elaborating on this base under different selection pressures.

It seems that perhaps I should read the book because, notwithstanding my comments, much of what you have said Churchland says sounds eminently sensible.