In his latest Response to Critics , Sam Harris spends some (too much) time on the nutbars before getting to the serious cases like Russell Blackford.
And before starting with his main response he provides this convenient summary:
For those unfamiliar with my book, here is my argument in brief: Morality and values depend on the existence of conscious minds—and specifically on the fact that such minds can experience various forms of well-being and suffering in this universe. Conscious minds and their states are natural phenomena, of course, fully constrained by the laws of Nature (whatever these turn out to be in the end). Therefore, there must be right and wrong answers to questions of morality and values that potentially fall within the purview of science. On this view, some people and cultures will be right (to a greater or lesser degree), and some will be wrong, with respect to what they deem important in life.
If this is accurate then I expect the answer to my earlier question is “no”, because there are no “right and wrong answers” to the question of how to relatively weigh the “various forms of well-being and suffering”.
But I’ll read the response further just in case.
At one point in his response, Harris draws a parallel with medicine and mockingly duplicates one version of his critics argument to show that there is no “science of medicine”. But in fact the analogy works to his disadvantage since the science of medicine does not tell us what to do in any particular situation. There are always costs countervailing any medical benefit and in many cases there is no way of determining the “best” choice without making an assignment of relative importance to competing values that is either essentially arbitrary or at least not in any way established by the science of medicine.
Similarly, although there are many ways science of some kind might provide helpful input for moral decision making by predicting outcomes (including various emotional ones) from our actions, there is probably no way of assigning relative importance to these. This is because it is highly unlikely that there is either any one dimensional notion of “well-being” for an individual or any meaningful way of accumulating even one emotional variable across multiple individuals.
In response to Blackford’s version of the weighting issue, Harris appeals again to the medical analogy, saying “Will there be disagreements between orthopedists who specialize in basketball and those who specialize in yoga? Sure. So what? We will still be talking about very small deviations from a common standard of “health”—one which does not include anencephaly or a raging case of smallpox.” But actually the unresolved “deviations” are not small, even in medicine, and it’s only the deviations that are morally challenging. (We probably don’t need science to convince most people that unleashing a global plague for no reason but the desire to see people suffer is outside the range of morally acceptable behaviour.)
Harris does understand that even with a well defined scalar objective function there may be multiple extrema, but he is completely without foundation for his claim that “radically disjoint peaks are unlikely to exist for human beings”. Our mutual similarity has no bearing on this as the “radically disjoint peaks” do not represent the unique optimal positions for different people but rather they are different possible positions that would maximize total well-being for the same global population. eg One might be a secular world in which we all have great freedom which comes at the cost of stressful choices and another might be a world of strictly (and sometimes harshly) enforced religious probity in which the loss of freedom (and suffering of punishment for some) is balanced by freedom from uncertainty (and a sense of strong moral superiority on the part of those sanctioning the punishment).
Finally, Harris responds to Blackford’s claim that abandoning a notion of scientifically provable moral truth “doesn’t prevent us developing coherent, rational critiques of various systems of laws or customs or moral rules, or persuading others to adopt our critiques.”
To this he says ” I consistently find that people who hold this view are far less clear-eyed and committed than (I believe) they should be when confronted with moral pathologies—especially those of other cultures—precisely because they believe there is no deep sense in which any behavior or system of thought can be considered pathological in the first place.” But in fact it is the hopeless task of trying to meet the impossible demand for scientific proof of their position that is crippling these people. Our moral values are true for us because we hold them. That is all we have and to doubt that it is enough is enough for us to lose it.