This blog entry is part 2 in a series on the moral argument. The entries in the series:
- The Moral Argument for God Part 1: Going from Morality’s Existence to God’s Existence
- The Moral Argument for God Part 2: Does Objective Morality Exist If God Does Not Exist?
- The Moral Argument for God Part 3: Does Objective Morality Exist?
- The Euthyphro Dilemma
- Epilogue: Awakening the Sensus Divinitatis
|Does Objective Morality Exist If God Does Not Exist?|
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A popular claim among proponents of the moral argument is “If God does not exist, then objective morality does not exist” (with some variants, e.g. “If God does not exist, then objective moral values and duties do not exist”). Here I’ll argue that this claim is correct.
A Brief Recap
While it’s better that one reads part 1 of the moral argument first, I’ll try to make this article a standalone entry and I’ll link some terms to the glossary for those who might be unfamiliar with them. I’ll also give a brief recap of stuff to know for this article.
By “descriptive ought” I mean that type of ought that is nothing more than some purely descriptive state of affairs, e.g. “If you want to do well in school, you ought to study” meaning something like “As a matter of practical necessity, you need to study to do well in school.” By “prescriptive ought” I mean that type of ought that is not a descriptive ought, e.g. “You should not to torture infants just for fun.” By “moral ought” I (roughly) mean the prescriptive ought as applied to human behavior. By moral properties being objective I mean that they exist independently of human belief and perception of them. Moral ontology is the discipline that studies the foundations of morality (e.g. are moral properties like moral wrongness physical or nonphysical?). Thus an ontological explanation of morality is an explanation of how morality exists and what sort of reality it constitutes.
What it means for moral properties to be non-natural varies between writers, but we can borrow philosopher Robert Adam’s description that it means moral properties “cannot be stated entirely in the language of physics, chemistry, biology, and human or animal psychology.” Either morality exists solely as part of the natural world (moral naturalism) or it exists to at least some degree as part of the non-natural realm (moral non-naturalism). One of these has to be true, because if morality exists neither as part of the natural realm nor as part of the non-natural realm, then it follows that morality does not exist as part of reality at all. If morality exists, some type of ontological explanation or other must be correct.
For the sort of morality we’re concerned with, moral non-naturalism appears to be true. Since physics, chemistry, etc. deal solely with purely descriptive states of affairs, natural properties and natural facts are purely descriptive states of affairs. As such, since moral oughtness is a prescriptive ought and not a descriptive ought, moral oughtness is non-natural and moral oughtness properties (like moral wrongness, where an action is morally wrong for someone only if they morally ought not to do it) are non-natural.
Another indication that moral properties are non-natural is their empirical undetectability and causal inertness. To illustrate what I meant by moral oughtness being empirically undetectable I used this thought experiment: imagine a moral nihilist (who disbelieves in moral oughtness) and a moral realist (who believes in moral oughtness) observe some jerk kicking a dog just for fun; the dog whimpers in pain and runs away. Both agree on all physiological and psychological facts, e.g. that the dog felt pain and suffered minor injury. The moral nihilist says, “I don’t think moral oughtness (like moral wrongness) is attached to that action.” The moral realist says, “I think moral oughtness (moral wrongness) is attached to that action.”
There is no empirical way to determine who is right here. Both views agree on all the same empirically observable facts, and moral oughtness being associated with certain physical facts (such as the dog’s injury) doesn’t explain any physical fact. Not only do we have zero empirical evidence for the existence of moral properties, we can’t have empirical evidence for moral properties since they’re empirically undetectable. The dog kicker scenario also illustrates that moral oughtness is causally inert. Notice that whether moral oughtness is associated with natural facts (e.g. the dog’s pain and injury) or not, the physical conditions are the same in both cases, and so barring the supernatural, the presence or absence of moral oughtness makes no causal difference as to what those physical conditions will result in.
In part 1 of the moral argument I noted that morality appeared to exist as part of the nonphysical realm to at least some degree (e.g. moral wrongness is a nonphysical property), and I argued that if we posited just one nonphysical thing as the foundation for objective morality and tried to find the simplest explanation for that entity grounding moral values and obligations, we end up with an eternal, transcendent, metaphysically necessary entity that imposes moral duties upon us with supreme and universally binding authority. This observation (and the claim that it rationally supports theism to at least some degree) is what I’ve called the argument from moral ontological simplicity. (For the purposes of understanding this article, the details of how this works are unimportant; I summarize it here only because I mention the argument later in this article.)
A Deductive Moral Argument
In my previous blog entry (part 1 of the moral argument) I gave an argument that went from morality’s existence to God’s existence, but that isn’t the only argument out there. Here’s another one:
- If God does not exist, then objective morality does not exist.
- Objective morality does exist.
- Therefore, God exists.
- If God does not exist, then objective morality does not exist (true premise)
- Objective morality does exist (true premise)
- God does not exist (false conclusion)
- Objective morality does not exist (from 1 and 3)
- Objective morality does exist and objective morality does not exist (from 2 and 4)
This blog entry will largely be about justifying premise 1 (in the next blog entry I’ll try to justify premise 2). For a while the first premise was unconvincing to me. Why can’t morality be like logic and just exist as a brute fact? I wasn’t convinced that God was needed for objective morality.
The Material Conditional
A material conditional takes the form of “If P, then Q” and is equivalent to “It is not the case that P is true and Q is false.” Thus, whether the material conditional is true is determined entirely by the truth of P and Q as follows, where the truth table below exhausts all possible true/false combinations of P and Q. Note the second line of the truth table where P being true and Q being false makes “If P, then Q” false:
|P||Q||If P, then Q|
To simplify, let’s reword “If God does not exist, then objective morality does not exist” as “If atheism is true, then objective morality does not exist,” so an “If P, then Q” material conditional here goes like this:
|P =||Atheism is true.|
|Q =||Objective morality does not exist.|
Recall the truth table:
|P||Q||If P, then Q|
One benefit of the material conditional is that it’s a theorem of mathematics and propositional logic that “Given P, probably Q” entails “Probably, if P then Q.” For example, “objective morality probably doesn’t exist if God does not exist” entails that the moral argument’s first premise is probably true. So if we establish that moral objectivism is unlikely on atheism, we’ll have strong support for the first premise.
For theists and those who deny moral objectivism then, the first premise is easy to justify; they just need to understand that the first premise is a material conditional and use a bit of logical thinking. Really, the only way to reasonably deny the first premise is to believe atheism is true and objective morality exists. So what about those people? For example, why couldn’t the atheist take my suggestion that objective morality’s existence is a brute fact?
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 Adams, Robert M. The Virtue of Faith (New York: Oxford University Press, 1987), p. 145.
Last major edit of this article: 2016-12-02-FR
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