Debunking Theories on Moral Realism - A Way Out

I presented this argument to a professor at the University of Colorado. It concerns the way that a moral realist can respond to theories that attempt to debunk moral realism.

Specifically, what it addresses is the claim that one can debunk moral realism itself by showing that it is grounded on a mistake. The most popular form of debunking comes from theories of evolution. The argument states that our beliefs about right and wrong are actually evolved sentiments and have nothing to do with right and wrong. Even if right and wrong existed - were real - there is no reason to believe that our evolved sentiments would track it. Instead, our evolved sentiments would track that which have, in a particular context, produced evolutionary fitness for those who had it. Thus, right and wrong do not exist - they are not real.

I commonly use this debunking argument against certain types of moral realism - those that state that our sentiments identify real value rather than being the evolved or learned desires and aversions. However, as the response below indicates, it does not defeat realism entirely. Even if these arguments work against certain types of realism, they do not work against all types of realism.

To give proper credit, I note that this response is an argument I pull out of J.L. Mackie's book Ethics: Inventing Right and Wrong It is not a conventional interpretation of Mackie, but I think I can defend it. It offers a realist response to debunking arguments and, insofar as Street et. al., are offering debunking arguments, I think it offers a realist response to them.

Let me start with some general statements.

Person 1 says P is true.
Person 2 says P is false.

The debunking theorist says that they are wrong. "P is true" and "P is false" are both false.

How can this possibly make sense?

P = (A & B)

Person 1 says (A & B) is true.
Person 2 says (A & B) is false because B is false.

We are going to assume, just for the sake of illustration, that B is true.

The debunking theorist debunks A. That is, the theorist shows that A is false. Thus, "A & B" is false because A is false. Also "'A & B' is false because B is false" is also false. The debunking theorist has shown that both statements are false.

Mackie illustrated this by reference to atoms. I offer that the best interpretation of Mackie's argument is illustrated as follows:

Person 1 says, "The mass of a hydrogen atom = m"
Person 2 says, "The mass of a hydrogen atom <> m"

Given the original meaning of the term "atom", an atom is without parts. Consequently, both of these statements may be rewritten:

Person 1 says, "The mass of a hydrogen atom = m and atoms are indivisible"
Person 2 says, "The mass of a hydrogen atom <> m and atoms are indivisible"

The debunking theorist comes along and argues that "atoms are indivisible" is false (debunking "atoms are indivisible").

Thus, Person 1's statement is false, and Person 2's statement is also false.

What is the realist response?

The response Mackie recommended was to redefine "atom" so that atoms could be divided. For example, one could offer, "An atom is the smallest piece of an element as such (e.g., of gold as such), which has a given number of protons for that element (hydrogen = 1 proton), and some variable number of neutrons, and electrons."

Once we make this change, it is possible for either Person 1 or Person 2 to be making a true statement, depending on what m is.

In changing the definition of atom, are we realists or anti-realists about atoms? Actually, we end up being both, at the same time. Under the new definition, we can be atomic realists - these atoms are real. But, under the old definition, we would be atomic nihilists or eliminativists (anti-realists). Actually, we have no non-ambiguous answer to the question, "Is atomic realism true?" It depends on what one means by "atom".

I want to apply this to the following example:

(1a) Adolf Hitler believes that genocide is permissible.
(1b) I, by contrast, believe that genocide is not permissible.

We turn this into something like:

(1a) "Adolf Hitler believes that genocide is permissible" and "right and wrong is determined by God's commands"
(1b) "I, by contrast, believe that genocide is not permissible" and "right and wrong is determined by God's commands"

The debunking theorist says that there are no divine commands. Hence, 1a and 1b are both false because the second conjunct in each case is false.

Please note that the second conjunct is not what the agent believes. It is a statement about what is true of right and wrong. Indeed, it is what the terms "right" and "wrong" mean, in the same way that "atom" literally meant "without parts". This is offered as a theory of what actually best explains and predicts the use of the terms.

(1a) "Adolf Hitler believes that genocide is permissible" and "right and wrong are intuitively or perceptually knowable moral properties"
(1b) "I, by contrast, believe that genocide is not permissible" and " right and wrong are intuitively or perceptually knowable moral properties"

The debunking theorist says that we have no intuitive knowledge of moral properties. Instead, we evolved dispositions to favor (or disfavor) certain states of affairs. Hence, 1a and 1b are both false because the second conjunct in each case is false.

The debunking theorist must not only show that they are targeting the theory that best explains and predicts the common use of moral terms, the debunking theorist must also be able to block all revisions to those terms of the type that chemists used when they decided that atoms had parts. Otherwise, the debunking theorist cannot complete that step from making an alethic challenge to making an epistemic challenge. Though the debunking theorist could take a defensive stance, haul up the draw bridge, and assert that they are willing to defend their position against all challengers (a challenger being somebody who offers an alternative account of the second conjunct).

When it comes to offering an alternative account of the second conjunct, please note that chemists were able to use "has parts" as an alternative to "has no parts". Granted, the only reason they could do this was because "has no parts" - even though it was a part of the meaning of the term 'atom' - had not been playing a significant role in their previous discussion about atoms. However, it does illustrate the range of alternatives that the debunking theorist must be prepared to defend against.

Ultimately, I think there is an alternative account debunking theorists cannot defend again. Indeed, it is very close to the alternative that I think Mackie offers. But, that is beyond the scope of this discussion.

(I know that Mackie is considered the paradigm error-theorist anti-realist. But he turns out to be an anti-realist about morality the same way that early chemists were anti-realists about atoms. Mackie was aware of how a realist could avoid this trap and, in fact, he took that route himself. The argument I attribute to him here is in Chapter 4 of Ethics: Inventing Right and Wrong, and it includes the "atom" analogy. Though this development has a lot more detail than Mackie provided.)