Outlining an Evolutionary Argument Against Moral Realism, On Materialistic Atheism

In a recent article on The Stream that’s proved controversial among some Christians on Facebook, I argued that gay activists who adhere to materialistic atheism cannot claim that homosexuality is really good. Part of the controversy I’ve faced has to do with the evolutionary argument I summarized there, suggesting that moral realism is impossible on materialistic atheism. At least one person on Facebook has called it a weak argument few philosophers would endorse.

Now, on the one hand that’s not surprising. It was a Stream column, not a philosophical treatise, so I didn’t lay out the entire argument. On the other hand, though, if the argument really fails, then I really want to know it. So here today I’m expanding the outline. Yes, it’s still in outline form, but with the steps filled in.

The primary point I’d want to make is under A, B, and C below: Moral realism is impossible on materialistic atheism, because in order for real right and wrong to exist, they would have had to come into being at some point, and materialistic atheism offers no sufficient cause for their beginning to exist.

By moral realism, I mean that some entities, actions, intentions, and outcomes are inherently good (good in themselves), others inherently bad (bad in themselves); and that they have these values with or without any human judgment agreeing or disagreeing with those values.

Part D presents a secondary conclusion: That words like “right” and “wrong” have no meaning or function except as labeling behaviors supporting human populations’ survival and reproduction. They are, in fact, nothing but labeling behaviors that serve that evolutionary purpose.

What follows here is my very unpolished, draft outline of the argument, published for your comments.

Given materialistic atheism:

A. The Genesis of Real Right and Real Wrong

1. Nothing exists except the material world of matter, energy, and their interactions in accordance with natural law.
2. Causation is closed: There are no effects but those which can be traced to material causes.
3. Moral evaluations such as “right” and “wrong” could not have meaningfully existed prior to the evolutionary arrival of sentient beings. It’s literally nonsense to suppose that any event or effect could have been either right or wrong, in deep evolutionary history, much less in the eternal past.
4. Having been previously nonexistent, real right and real wrong could not exist today unless they began somehow to exist. (See comment 1.)
5. Some sufficient cause is necessary in order for real right and wrong to begin to exist.

B. The Locus of Right and Wrong

1. Right and wrong (whether subjective or objective) have meaning only in relation to sentient beings.
2. The existence of sentient beings is ultimately explained by matter and energy interacting according to natural law, and nothing but that.
3. More proximately, the existence, form, and behaviors of sentient beings are fully explained through neo-Darwinian processes of random variation and natural selection.
4. Therefore right and wrong exist only in relation to sentient beings, and only as a product of random variation and natural selection.

C. Evolutionary Processes, Causal Closure, and Moral Realism

1. Random variation happens strictly in the realm of biochemistry, and biochemistry does not have the causal resources to cause rightness or wrongness to begin to exist. Therefore random variation is not the sufficient cause, required per A.5.
2. Natural selection selects for, and metaphorically produces or creates, adaptive biological and behavioral features and functions, oriented strictly toward a single end: success in populations’ survival and reproduction.
3. Natural selection’s capabilities extend only to the point of supporting survival and reproduction. Its capacities do not include the ability to make survival and reproduction either right or wrong, good or bad. Therefore natural selection is not the sufficient cause, required per A.5.
4. With respect to biological and behavioral features and functions, causation is closed on random variation and natural selection (with negligible contributions logically possible by sheer chance).
5. Therefore there is no sufficient cause capable of causing real rightness or wrongness to begin to exist. (See comment 1 for more.)
6. If real rightness or wrongness is not eternally existent (A.3.) and has not begun to exist (C.5.), then it does not exist now. Moral realism is not real.

D. Labeling Behaviors

1. Evolution has, however, produced behaviors in humans whereby we label acts, intentions, and outcomes as good, bad, right, wrong, etc.
2. These behaviors must have sufficient reasons explaining their existing in humans.
3. With causation being closed as stated above, those sufficient reasons must be located in the realm of natural selection.
4. Natural selection has only one capability, however: Supporting success in survival and reproduction.
5. Therefore humans’ labeling behaviors must be an outcome of natural selection’s support for survival and reproduction.
6. With no other cause on hand to produce other purpose or value attached to these labeling behaviors, these behaviors could not possibly have any other purpose or value.
7. Therefore “good,” “bad,” “right,” and “wrong” are strictly and entirely labeling behaviors whose only purpose is to support human populations’ survival and reproduction.
8. And since that is all that these behaviors are, given their genesis via naturalistic evolution, they could not possibly have any reference to real right or real wrong.

And that would seem to entail that there is no real right or real wrong, given naturalistic evolution.

But I’m open to your comments. Thank you.

Update: I’ve just discovered this site is having trouble accepting comments. Please comment on Facebook in the meantime instead. Fixed. Needed a database table repaired.

Image Credit(s): Steinar Engeland/Unsplash.