One cannot make truth claims about morality because moral perceptions are subjective manifestations of evolved behavioral traits. That fact should have been obvious to any rational human being shortly after the publication of The Origin of Species in 1859. It was certainly obvious enough to Darwin himself. Edvard Westermarck spelled it out for anyone who still didn’t get it in his The Origin and Development of Moral Ideas, published in 1906. More than a century later one might think it should be obvious to any reasonably intelligent child. Alas, most of us still haven’t caught on. We still take our occasional fits of virtuous indignation seriously, and expect everyone else to take them seriously, too. As for the “experts” who have assumed the responsibility of explaining to the rest of us when our fits are “really” justified, and when not, well, it seems they’ve never heard of a man named Darwin. Or at least it does to anyone who takes the trouble to thumb through the pages of the journal Ethics.
You might describe Ethics as a playground for academic practitioners of moral philosophy. They use it to regale each other with articles full of rarefied hair splitting and arcane jargon describing the flavor of morality they happen to prefer at the moment. Of course, it also serves as a venue for accumulating the publications upon which academic survival depends. Look through the articles in any given issue, and you’ll find statements like the following:
The reasons why actions are right or wrong sometimes are relatively straightforward, and then explicit moral understanding may be quite easy to achieve.
Since almost all civilians are innocent in war, and since killing innocent civilians is worse than killing soldiers, killing civilians is worse than killing soldiers.
We are constrained, it seems, not only not to treat others in certain ways, but to do so because they have the moral standing to demand that we do so, and to hold us accountable for wronging them if we fail.
Some deontologists claim that harm-enabling is a species of harm-allowing. Others claim that while harm-enabling is properly classified as a species of harm-doing, it is nonetheless morally equivalent, all else equal, to harm-allowing.
Do you notice the common thread here? That’s right! All these statements are dependent on the tacit assumption that there actually is such a thing as moral truth. In the first that assumption comes in the form of a statement that implies that what we call “good” and “evil” actually exist as objective things. In the second it comes in the form of an assumption that there is an objective way to determine guilt or innocence. In the third it manifests itself as a belief the moral emotions can jump out of the skull of one individual and acquire “standing,” so that they apply to other individuals as well. In the fourth, it turns up in the form of a standard by which it can be determined whether acts are “morally equivalent” or not. Westermarck cut through the fog obfuscating the basis of such claims in the first chapter of his book. As he put it,
As clearness and distinctness of the conception of an object easily produces the belief in its truth, so the intensity of a moral emotion makes him who feels it disposed to objectivize the moral estimate to which it gives rise, in other words, to assign to it universal validity. The enthusiast is more likely than anybody else to regard his judgments as true, and so is the moral enthusiast with reference to his moral judgments. The intensity of his emotions makes him the victim of an illusion. The presumed objectivity of moral judgments thus being a chimera, there can be no moral truth in the sense in which this term is generally understood. The ultimate reason for this is that the moral concepts are based upon emotions, and that the contents of an emotion fall entirely outside the category of truth.
In other words, all the learned articles on the merits of this or that moral system in the pages of Ethics and similar journals are more or less the equivalent of a similar number of articles on the care and feeding of unicorns, or the number of persons, natures and wills of imaginary super-beings. Why don’t these people face the obvious? Well, perhaps first and foremost, because it would put them out of a job. Beyond that, all their laboriously acquired “expertise,” would become as futile as the expertise of physicians in the 18th century on the proper technique for bleeding patients suffering from smallpox. For that matter, most of them probably believe their own cant. As Julius Caesar, among many others, pointed out long ago, human beings tend to believe what they want to believe.
Morality is what it is, and won’t become something different even if the articles in learned journals on the subject multiply until the stack reaches the moon. What would happen if the whole world suddenly accepted the fact? Very little, I suspect. We don’t behave morally the way we do because of the scribblings of this or that philosopher. We behave the way we do because that is our nature. Accepting the truth about morality wouldn’t result in a chaos of moral relativism, or an astronomical increase in crime, or even a sudden jolt of the body politic to the right or the left of the political spectrum. With luck, a few people might start considering the implications of the truth, and point out that all the virtue posturing and outbursts of pious wrath that are such a pervasive feature of the age we live in are more or less equivalent to the tantrums of children. The result might be a world that is marginally less annoying to live in. I personally wouldn’t mind living in a world in which the posturing of moral buffoons had become more a source of amusement than annoyance.
RIght now there is a book on my desk. I take my perception of that book to be what you call “a subjective manifestation of an evolved behavioral trait”. Does this mean I cannot make truth claims about it?
Without getting down in the epistemological weeds, I would say you can make truth claims about the book as an object that exists as a thing-in-itself, independent of your mental processes. Good and evil are not things-in-themselves in that sense.
That does not mean that one cannot make truth claims about the mental processes themselves. As Westermarck put it,
“If there are no general moral truths, the object of scientific ethics cannot be to fix rules for human conduct, the aim of all science being the discovery of some truth. It has been said by Bentham and others that moral principles cannot be proved because they are first principles which are used to prove everything else. But the real reason for their being inaccessible to demonstration is that, owing to their very nature, they can never be true. If the word “Ethics,” then, is to be used as the name for a science, the object of that science can only be to study the moral consciousness as a fact.