Compared to some of my earlier blogs this one will presume quite a bit of philosophical understanding. Even then since I am introducing a slightly new idea it will still be slow going. But I am happy to answer questions anyone may have in understanding. Also any editing advice is always appreciated.
Earlier I have referenced Richard Joyce, Sharon Street and Mark Linville as philosophers who have published arguments that if evolution (and naturalism) are true then any beliefs we have about real morality would be unreliable.
Here are some of their articles on the issue:
Sharon Street’s verision
A version by Richard Joyce
Here some of his other papers – many of which address this argument.
Linville gives much more than just the epistemic argument he also covers allot more ground.
This blog will attempt to advance that argument in light of a common objection.
By the way this argument not only tends to show why natural selection will not hone in on moral truths but also why science will have its efficacy limited as well. Specifically it will explain why science can’t identify the actual rightness or wrongness. After we determine what we deem right and wrong science will of course be very helpful in promoting or determining whether a set of facts fits that description. But there will always remain a critical part of the analysis that science cannot help.
One of the common responses to the argument given by Joyce, Street, and Linnville is given in this blog (here he is responding to Street):
In the end that author thinks there are 2 ways the naturalist can save moral beliefs he says:
“This is not to say that natural selection does not pose a challenge to moral realism. Street’s coincidence objection will kick in again unless the moral realist can either a) show there are at least some evaluative judgments which are not simply the result of more basic evaluative tendencies that have been shaped by evolutionary pressures (or better, are inconsistent with an evaluative judgment under reflective equilibrium that takes into account all tendencies but falls short by virtue of some form of moral reasoning that only the realist can supply); or b) show why tendencies that are clearly the result of evolutionary pressures so neatly line up with the results of a capacity for evaluative judgment that is supposed to be unrelated to such tendencies (what Street calls “tracking”). For (a) to be the true, it cannot be the case that our system of values cannot be as thoroughly “saturated” with the influence of natural selection as Street thinks it is. One option for (b) is to argue that adaptiveness and what is “good” are systematically related in such a way that selective pressures will tend to produce a tendency to true evaluative judgments. After all, what is adaptive is arguably a species of the good (although it’s possible that this line of thought leads us back to a constructivist account by relativizing the good to the constitutions or organisms).”
I personally do not think A accomplishes anything, but I won’t address that here. In this paper I argue that approach B is necessarily doomed to failure. Evolution, and incidentally science, cannot possibly track the truth of ultimate questions of real morality.
I’ll just throw a form of the argument on the table and then I will talk more about what it means:
P1) The process of natural selection (and science) is blind (insensitive) to concepts/truths/facts that never have material or empirical manifestations or indicia.
P2) Moral evil is a fact/concept/truth that has no material or empirical manifestations or indicia.
C1) Therefore the process of natural selection (and science btw) is blind (insensitive) to moral evil.
First I will talk a bit about what I mean by these terms and where the argument is aimed, and then I will address the likelihood of these premises being true.
By “blind” or “insensitive” I mean the processes do not track the truth of the concept. There can be no cause and effect relationship between that truth and the process of evolution (or science).
“Moral Evil” could be substituted for “moral wrongness” “moral goodness” “moral truths”. Although the term “moral facts” is used by most philosophers in this area, it is to my mind, a poor word choice. I think “wrongness” helps us focus in on what I am talking about better than the alternatives. I use that term a bit and by wrongness I mean moral wrongness.
Let me explain more about what I mean by “material or empirical manifestations or indicia” Those who argue for the reliability of moral beliefs often make the very general claim roughly along the lines of:
Mechanisms that tend to produce true beliefs will generally be more adaptive than those producing false ones. Therefore the mechanism(s) that produces our moral beliefs, likely tends to produce true beliefs.
The attempt is to sort of shift the burden to those who claim moral beliefs are an exception to the rule. The validity of this move is suspect but my argument, more or less, accepts the challenge. What is it about moral beliefs that would exempt it from the reliability we afford other forms of knowledge?
My position is that in every moral analysis there is going to be a critical determination, the truth of which has no material or empirical component. Without such a component natural selection (and science) will be blind and insensitive to it, and therefore can’t possibly track it.
Let me give an example to help illustrate what I mean by material manifestation of wrongness. Let’s say Leslie complained that her roommate Sophia used sticky traps to catch a mouse. She thought this was not morally acceptable because sticky traps, unlike other traps, left the mouse to suffer longer. Now let’s just assume Sophia thought her actions were morally acceptable. Perhaps Sophia either didn’t place as much moral consequence on the mouse’s suffering or perhaps she thought the effectiveness or the inexpensiveness of the traps outweighed the suffering. Hopefully all moral realists can agree Sophia’s use of the sticky trap was either morally acceptable or it was not.
Now it seems very clear to me that both parties can be fully informed and agree about everything our five senses can tell us about this event and still disagree on whether it is morally acceptable. That is Sophia can be well aware that the mouse will suffer longer. (and indeed Sophia might believe the added suffering from the sticky trap might be greater than what Leslie thinks) Leslie can be well aware of the decrease in the efficiency, and the added cost, of other types of traps. (and Leslie might even think sticky traps are relatively less expensive and more efficient than Sophia thinks.) They might both fully understand the neurology of mice and therefore understand how mice suffer in sticky traps as opposed to other traps etc. Take any piece of information we can find out from our senses about this event and we can assume they both fully understand it and still disagree whether it was morally acceptable. Because the actual “wrongness” of an action never has a material or empirical manifestation science will never be able to resolve this dispute.
It’s not like they can watch a recording of the events through a certain type of projector and the video will show with a red tint if Sophia was wrong and a green tint if what she did was morally acceptable. Nor can we examine of the mouse’s liver or other organs to determine whether the killing was justified. We can determine how it died and from there we might have certain beliefs about wrongness that lead us to believe it was killed through immoral means. But we can’t see “the wrongness” itself. Nor does “the wrongness” itself leave empirical indicia. 
I believe Sharon Street is on to something of the same point when she separates out moral beliefs from beliefs about a creatures “manifest surroundings”:
“What makes this point somewhat tricky is that on the face of it, it might seem that of course it promotes reproductive success to grasp any kind of truth over any kind of falsehood. Surely, one might think, an organism who is aware of the truth in a given area, whether evaluative or otherwise, will do better than one who isn’t. But this line of thought falls apart upon closer examination. First consider truths about a creature’s manifest surroundings—for example, that there is a fire raging in front of it, or a predator rushing toward it. It is perfectly clear why it tends to promote reproductive success for a creature to grasp such truths: the fire might burn it to a crisp; the predator might eat it up. But there are many other kinds of truths such that it will confer either no advantage or even a disadvantage for a given kind of creature to be able to grasp them. Take, for instance, truths about the presence or absence of electromagnetic wavelengths of the lowest frequencies. For most organisms, such truths are irrelevant to the undertakings of survival and reproduction;…”
It is my contention that moral truths never have a material manifestation and therefore evolutionary processes cannot possibly track them.
In his paper “Ethics and Observation” Gilbert Harman asked the question “you can observe someone do something but can you ever perceive the rightness or wrongness of what he does?”
I think this question is somewhat ambiguous because of the word “perceive.” We tend to say we “perceive” this is right or wrong but I think it’s quite clear that we don’t use any particular one of our five sense perceptions to do it. So I think if he asked a question “you can observe someone do something but can you ever hear the rightness or wrongness of what he does?” or “you can observe someone do something but can you ever taste the rightness or wrongness of what he does?” we could easily answer the questions in the negative. The same would be true if he asked if we see, touch, or smell the rightness/wrongness. We can’t do these things because there’s no “material/empirical manifestation” of rightness or wrongness. To the extent one claims we can possibly “see” the wrongness I think he is exchanging “see” for “judge” the wrongness. Wrongness is not a color.
Ok so at this point you might be wondering about other areas of knowledge. How does the truth “manifest itself” in other areas of belief?
Sharon dealt with the more obvious case of evolution tracking the truth for our beliefs about our immediate material surroundings.
Dr. Harman gave a good example to illustrate the point dealing with science. He says “let’s consider a physicist making an observation to test a scientific theory. Seeing a vapor trail in a cloud chamber he thinks, ‘there goes a proton.’”
Well in this case, as in any case when we are trying to detect the very existence of a material thing, the truth of that material things existence will materially manifest itself in the existence of that material thing. Here the proton itself is not observed but it’s material manifestation is observable by the vapor trail in the cloud chamber. Thus although the proton itself may not directly manifest itself to our senses there is a material manifestation of the truth that there is a proton. One such “material manifestation/indicia” is the vapor trail. So it would be at least possible that Natural selection could create mechanics that track the truth of protons existing.
Next let’s look at math. I think there is a sense that certain mathematical truths just appeared to be self-evident. But setting aside self evidence, I think Richad Joyce and Dr. Harman also establish how mathematical truths have material manifestations.
Consider what Dr. Harman said in this regard:
“Perhaps ethics is to be compared, not with physics, but with mathematics. Perhaps such moral principles as you want to keep your promises is confirmed or disconfirm them the same way (whatever it is) in which a mathematical principle as “5+7=12” is. Observation does not seem to play the role and mathematics it plays in physics. We do not and cannot perceive numbers, for example, since we cannot be in causal contact with them. We do not even understand what it would be like to be in causal contact with the number 12, say. Relations among numbers cannot have any more of an effect on our perceptual apparatus than moral facts can.
Observation, however is relevant to mathematics. In explaining the observations that support a physical theory, scientists typically appeal to mathematical principles. On the other hand, we never seem to need to appeal in this way to moral principles. Since an observation is evidence for what best explains it, but since mathematics often figures in the explanation of scientific observations, there is indirect observational evidence for mathematics. There does not seem to be observational evidence, even indirectly, for basic moral principles. In explaining why certain observations have been made, we never seem to use purely moral assumptions. In this respect then, ethics appears to differ not only from physics but also from mathematics.”
Joyce gives what I consider another example of mathematics having a material manifestation. He states:
“Suppose you are being chased by three lions, you observe two quit the chase, and you conclude that it is now safe to slowdown. The truth of “one plus one equals two” is a background assumption to any reasonable hypothesis of how this belief might have come to be innate.” The Evolution of Morality Richard Joyce page 182.
Joyce’s example of running from lions demonstrates a ”material manifestation” of the mathematical truth that 3-2=1. That mathematical truth manifests itself in that 3rd lion. Mathematical truths would no doubt “manifest themselves” in trade as well. If you do not understand that seven is more than five when someone was, say, bartering food stuffs there would be a material manifestation in that you might lose lots of your food.
Due to these material manifestations we have reason to believe natural selection might be reliable in creating belief mechanisms regarding our manifest surroundings, science and math (logical truths have material manifestations in a similar way to math). But moral judgments lack those material components and therefore any mechanism yielding moral truths would lack the reason we might find them reliable.
Now let me say the fact that people hold beliefs about morals often does have material manifestations (eg., the creation of laws and posses) This is undoubtedly true. . I don’t doubt our beliefs can have material manifestations. They will have them whether they are true or false. But how did those beliefs arise? That is the question. Since it seems clear the truth of those beliefs could not possibly be tracked by evolution then our beliefs are not reliable. (edit: I address this a bit more in my reply to Travis’s first comment on this blog.)
With that readers may have a few more questions about what I mean by “material manifestations” I would encourage people to go ahead and ask in the comment section.
At this point I would like to address whether the premises are true.
Is the first premise true? Natural selection concerns itself with things that have physical /empirical impacts. Only things with physical or empirical impacts, can effect whether things are killed or procreate. I am not sure this will be much in dispute so I won’t dwell on it. The same I think would be true with the idea that science concerns itself with empirical data. If you can’t test it with empirical data then it’s probably not science.
I anticipate more reluctance to accept the second premise.
Moral naturalists might argue that the natural facts that they believe simply make up moral facts and they do indeed have physical and empirical manifestations and indicia. For example facts that might make up a murder (i.e., a “wrongful” killing) might include the fact that the murderer knew firing his gun would likely kill the victim. It would include the fact that the bullet from his gun did in fact go through the victim etc etc. All of which could have various empirical indicia. However we still need to make the determination that the set of facts I described belongs to the set of facts which are also moral facts.
We still need to differentiate the set of natural facts that happen also to be moral facts. The “wrongness” made up of one set of natural facts leaves no additional physical or empirical indicia which we can see hear taste etc. In fact the wrongness does not even exist outside the other natural properties so it couldn’t signal us to this set of facts as being ones upon which moral facts supervene.
As Street points out “The [Moral Naturalist] response, I will argue, ultimately just puts off a level the difficulties raised…..” “In trying to figure out which natural facts evaluative facts are identical with, we have no option but to rely on our existing fund of evaluative judgments…”
One person might say that the set of natural properties called set “n” equates to evil. Another might disagree. They might both fully acknowledge the empirical properties of the set yet still disagree on the whether the set properly has evil supervene on it. In the end this problem is most difficult for the naturalist precisely because he argues there is no additional property of wrongness. The wrongness is just the set of natural facts that make up the wrong action. (or sets of sets of wrong actions) Accordingly, there can be no physical or empirical manifestation or indicia, that the wrongness leaves behind, that would help evolution select for the correct set(s) of facts that match up with moral facts.
Because moral naturalists posit no additional properties other than the natural properties that make up the set of a wrong action, there could be no additional material indicia that would result from the set of natural properties which would help natural selection distinguish the moral sets.
Again just to be clear when I talk about moral truths I mean only the wrongness or rightness of a particular action. No doubt we have material indicia of the fact that the World Trade Center Towers were attacked. However we have no material indicia of the very wrongness of that act. There is no buzzing sound or red tint that we hear or see when we are witnessing an evil act. We learn of the events and we judge them to be wrong.
What about non-naturalists?
Nevertheless some might argue that we can’t say for sure whether our moral beliefs cannot be traced to empirical evidence. (material manifestations) They might say “Who knows? After all, a lot goes on in our brains when we see something.” I think those who doubt the truth of premise 2 are simply misunderstanding the nature of moral truths. I think the following thought experiment may help demonstrate this point.
Consider the possibility that they are right. Let’s just pretend every time we perceive a wrong action the wrongness emits some, hitherto unknown, type of radiation. This radiation causes the “unease” we feel when we perceive an immoral act. Every time we see an immoral act on television, or simply imagine one, our brain would apparently trigger the memories which bring about the same type of unease and belief again.
Okay it’s an outlandish idea but the point is not to suggest that this is plausible. My point, is that if this were to occur it would not give additional justification to our moral beliefs. It would just as likely debunk them. We would just as likely understand that the reason we believe things are immoral is due to this physical trigger and not because it is really wrong.
The fact that we might reach this conclusion demonstrates that our conception of moral truth does not allow for material manifestations or indicia. It is simply not part of the concept. Since material manifestations and indicia are not part of moral truths, natural selection could not possibly track moral truth.
 I might say that evil does not occupy space or exist in any particular space. Yes it exists when an occurrence happens but it is not a something that literally surrounds the occurrence. It’s a property that seems to exist at no particular point of space at all. When we consider a long embezzlement conspiracy would we think the evil was literally located all through the offices and everywhere the people perpetrating it conspired? If they talked on the phone was evil in the phone wires? I don’t really think so. I’m not exactly sure if this is a proper way to express what I am saying but it might be a at least a start.