I’ve already discussed how unconvincing I find William Lane Craig’s Moral Argument for God, so it is interesting that there is a cousin to this argument that I find compelling, the Argument from Moral Knowledge:
- We have knowledge of objective morals.
- If we have knowledge of objective morals, all other things being equal, God probably exists.
- Therefore, all other things being equal, God probably exists.
Premise 1 will be unobjectionable to almost anyone that is committed to objective morals; it would be altogether strange to assert that there are moral facts, but we cannot know them. Disagreements notwithstanding, we reflect upon circumstances and know whether a course of action is right or wrong. Psychopaths don’t have the knack for this, but most of us are not so inhibited.
Premise 2 relies upon an argument to the best explanation: which explains moral knowledge best, theism or atheism? This is why its consequent is “all other things being equal, God probably exists.” When faced with two otherwise equally attractive explanations for a state of affairs, the explanation that accounts for the breadth of the evidence, is simplest, least ad hoc, etc. should garnish our belief.
We should keep in mind that the best explanation is not always the right one. Some ancient Greek astronomers reasoned that the sun must orbit the earth because if the earth orbited the sun, observations of stars would be influenced by parallax. In other words, geocentricism best explained the lack of observed stellar parallax. This was a perfectly reasonable argument to the best explanation, given the instrumentation available at the time. But of course geocentricism is false (and stellar parallax can be observed–with a telescope).
Now the theist can explain our moral knowledge very simply. God knows the moral facts, and He so constitutes us to have a similar moral faculty (though ours may not function so well as His).
There are non-theist or quasi-theist anthropologies that can explain our moral faculty. Platonism, for instance. For Plato, we have all our knowledge through our connection to the Forms (e.g. I know I am sitting on a chair because I understand what it is for a thing to be chair by reflecting upon the Form of Chair). The highest form is The Good, and we know objective morals through our connection to it (How does Plato explain our knowledge of the Forms? We reincarnate and between lives our souls are immersed in the Realm of the Forms.).
But Platonism is a close cousin to theism. Indeed, Plotinus, Philo, Augustine, and other later Platonists located the Forms as thoughts within a divine mind. More importantly, just about every non-theist today finds Platonism unattractive. Rather, non-theists overwhelmingly believe humans emerged through a long process of evolution through natural selection.
Now we can provide evolutionary explanations for why we believe altruism is right and incest is wrong or why we behave in altruistic ways and do not behave in incestuous ways, but that is not the same as explaining how it is that we have a faculty for knowing objective morals. A creature programmed by evolution would just be reflecting upon its programming.
Let me explain by comparison to a similar, but I think fallacious, argument offered by Alvin Plantinga, his Evolutionary Argument Against Naturalism. Plantinga tries to show that naturalism (i.e. denial of God and other supernatural entities) and belief in evolution are opposed because a species that arose through evolution without the aid of God would not have faculties for reliably knowing that either evolution or naturalism is the case. Rather, purely evolved faculties would only track what best facilitates survival and reproduction. Whereas, if God existed, He would be able to so design our faculties so that they do, on the whole, track the truth.
But Plantinga’s argument encounters difficulty because we would expect evolution to, on the whole, furnish faculties that track the truth because true beliefs, in general, facilitate survival and reproduction. Organisms that grossly over-estimate or under-estimate that presence of predators will waste energy fleeing from delusions or get eaten. Organisms that cannot detect the suitability of mates, will produce defective offspring or none at all.
We might expect that rather more of our beliefs would be true if they benefit from divine curation, but this difference doesn’t explain why a belief in naturalism would be a confusion when held by members of a purely evolved species. Furthermore, as Eliot Sober and Branden Fitelson have argued, cognitive science indicates that we deploy biases and heuristics that allow us to reach conclusions quickly, but those conclusions are often mistaken (a very excellent book on that topic). Beings with a bevy of systematic cognitive errors are more likely to have arisen trough pure evolution rather than evolution guided by a trustworthy God.
The Argument from Moral Knowledge is not vulnerable to the same difficulties because not every kind of truth is evolutionarily equal. We understand that evolution would hone our senses and rational faculties so that they in general track the truth, but natural selection does not select for objective morals tracking.
Should we admit that objective morals are nothing more than our evolved social mores? That would save morality from pure subjectivism because evolved behaviors and beliefs enjoy a life within a species. They are not just the preferences of individuals.
But this does not mesh with our moral knowledge. Evolution has programmed sharks to prey on their young and mantises to prey on their mates. Penguins practice necrophilia, pedophilia, and steal each other’s young. Humans by and large, are not so depraved, but if all there is to morality is evolutionary programming our non-depravity is just a fluke and our moral knowledge delusional.
So I’m stuck with the conclusion that, all other things being equal, God probably exists. I’ll later discuss what this conclusion means for my beliefs.