Post Author: Bill Pratt 

Moral skeptics frequently argue that evolution has tricked us into thinking that our moral judgments are based on mind-independent moral facts. Even though it seems like our moral judgments are examples of authentic reasoning, they are not. Joshua Greene is a typical voice of moral skepticism:

Moral judgment is, for the most part, driven not by moral reasoning, but by moral intuitions of an emotional nature. Our capacity for moral judgment is a complex evolutionary adaptation to an intensely social life. We are, in fact, so well adapted to making moral judgments that our making them is, from our point of view, rather easy, a part of “common sense.” And like many of our common sense abilities, our ability to make moral judgments feels to us like a perceptual ability, an ability, in this case, to discern immediately and reliably mind-independent moral facts. As a result, we are naturally inclined toward a mistaken belief in moral realism. The psychological tendencies that encourage this false belief serve an important biological purpose, and that explains why we should find moral realism so attractive even though it is false. Moral realism is, once again, a mistake we were born to make.

Although we may think we are making moral judgments based on mind-independent moral facts, this is imply an illusion caused by evolution. We are simply mistaken to think that moral facts actually exist. According to “New Atheist” Sam Harris, “Greene alleges that moral realism assumes that ‘there is sufficient uniformity in people’s underlying moral outlooks to warrant speaking as if there is a fact of the matter about what’s ‘right’ or ‘wrong,’ ‘just’ or ‘unjust.’’

Harris asks:

But do we really need to assume such uniformity for there to be right answers to moral questions? Is physical or biological realism predicated on “sufficient uniformity in people’s underlying [physical or biological] outlooks”? Taking humanity as a whole, I am quite certain that there is a greater consensus that cruelty is wrong (a common moral precept) than the passage of time varies with velocity (special relativity) or that humans and lobsters share a common ancestor (evolution). Should we doubt whether there is a “fact of the matter” with respect to these physical and biological truth claims?

Greene concludes that moral intuitions cannot be trusted, but that science can:

[M] oral theorizing fails because our intuitions do not reflect a coherent set of moral truths and were not designed by natural selection or anything else to behave as if they were … If you want to make sense of your moral sense, turn to biology, psychology, and sociology— not normative ethics.

Is this true? Did natural selection fail to design moral truth tracking, but succeed in designing biological, psychological, and sociological truth tracking? In other words, did evolution bequeath us the ability to discover mind-independent, objective facts about non-moral domains of knowledge? Harris argues that this is a dangerous move for the moral skeptic to make. The price to be paid is high. Harris explains:

This objection to moral realism may seem reasonable, until one notices that it can be applied, with the same leveling effect, to any domain of human knowledge. For instance, it is just as true to say that our logical, mathematical, and physical intuitions have not been designed by natural selection to track the Truth. Does this mean that we must cease to be realists with respect to physical reality?

Deny that moral facts exist and you end up having to deny that truths of any kind exist. There is no way, says Harris, to argue that evolution gave us the ability to know facts about logic, math, and physical reality, while at the same time fooling us about the existence of moral facts. It’s a package deal, like it or not.