Premise 1. Morals and values are physically dependent (without remainder) on the nature of any would-be moral agent (such that given the nature of an agent, a certain set of values will necessarily obtain, and those values will then entail a certain set of morals).
Premise 2. By its own intrinsic nature, the most overriding value any conscious agent will have is for maximizing its own well-being and reducing its own suffering. This includes not just actual present well-being and suffering, but also the risk factors for them (an agent will have an overriding interest in reducing the risk of its suffering as well as its actual suffering; and likewise in increasing the probability of its long-term well-being as well as its present well-being).
Premise 3. All of the above is constrained (and thus determined) by natural physical laws and objects (the furniture of the universe and how it behaves).
Premise 4. The nature of an agent, the desires of conscious beings, and the laws of nature are all matters of fact subjectable to empirical scientific inquiry and discovery. (Whether this has been done or not; i.e. this is a claim to what science could do, not to what science has already done.)
Conclusion: Therefore, there are scientifically objective (and empirically discernible) right and wrong answers in all questions of moral fact and value (i.e. what values people have, and what morals those values entail when placed in conjunction with the facts.Carrier reassures us that the full argument on which the above summary is based is deductively valid, as testified by “four philosophy professors” who examined it before it was published in a chapter of The End of Christianity (ed. by John Loftus), which Carrier, in his own inimitable style, tells us ought to be required reading for anyone engaging in this sort of debate. Whatever. I find it ironic that later on in the same essay Carrier disparages the academic peer review process, apparently except in the case of his own papers. [He says, and I quote: “Academic peer review (for books and journals in philosophy) simply does not look for, nor even rewards, best cases. They just publish any rubbish that meets their minimal standards (and those standards are not very high, relatively to where they could be).”]