Saturday, July 5, 2014

Denying Both Premises of the Moral Argument

Behold the deductive moral argument (or at least one variety of it):
  1. If God does not exist, then objective morality does not exist.
  2. Objective morality does exist.
I’ve seen a number of atheists claim both premises to be false. In this article I’ll give an informal proof to explain why that is impossible.

In a way this article is redundant, since I gave a formal proof for the falsity of both premises being logically impossible in part 2 of my introductory logic series, with part 2 also explaining the basic symbolic logic and various rules of logic needed to understand the proof (thus it isn’t necessary to read introductory logic part 1 to understand the proof, though it wouldn’t hurt either). So what inspired me to write this article to present a more informal proof?

Inspiration



In one Facebook dialogue somebody denied both premises. I said it was logically impossible for both premises to be false, and gave a link that had the proof of this in symbolic logic while noting, “If you’re not well-versed in formal logic, not to worry, because the article gives a crash course of some symbolic logic rules.” His first response to this was to ignore the proof entirely while saying there is “no reason” why one can’t reject both premises. I pressed further to get him to respond to the logical argument against both premises being false, but he seemed to have little motivation to learn the logic and understand the objection (judging from e.g. him saying “I will attempt to go back over this at some point, but I really have very little motivation to do so”). It’s this sort of behavior that temps me to embrace the stereotype of atheists being irrational and giving lip service to logic while in reality having little real interest in learning it (at least when they discover it might be used against them).

But that’s a temptation I’m going to resist. I realize my articles introducing logic require a bigger time investment than reading a 100-word Facebook post, and that not everybody is interested in learning formal logic despite the benefits of doing so (e.g. helping one to think more logically). So in this post I’m going to distill some of the reasons of the logical proof in plain English.

Understanding the First Premise



For brevity’s sake I’ll abbreviate “objective morality” as OM. By morality being objective I mean that moral truths hold independently of human belief and perception of them (this matches closely with how “objective morality” is often defined in the context of the moral argument[1]). Behold the first premise:
  1. If God does not exist, then OM does not exist.
Among the bad objections against the moral argument are straw men and red herring fallacies against the first premise. So to help prevent that, I’ll note what the first premise is not saying. It is not saying that God grounds morality—even some atheists agree with the first premise and they don’t believe God grounds anything. Nor is the first premise saying it is impossible for OM to exist in the absence of God; it merely says it isn’t the case that OM exists without God.

If it’s hard to see why that would be true here’s another way to look at the first premise. It is important to understand that whether we should believe an if-then statement often depends on the background information we possess, e.g. If it rained heavily in the last five minutes, then Sam’s car is wet depends on factors like whether Sam’s car is in a garage. Similarly, if you believe this equation is true…
God does not exist + background info = OM does not exist
…then you believe If God does not exist, then OM does not exist and to think otherwise is to misunderstand the meaning of the first premise. The first premise is not saying it is impossible for OM to exist without God, only that given the facts of the real world we are in OM does not exist if God does not exist.

The Proof



Let =entails⇒ signify “entails (by the rules of logic).” For example:
I have a hand and I have a leg =entails⇒ I have a leg
The above is true thanks to a rule of logic known as simplification (which I explain in introductory logic part 1).

A very important fact in the proof is this: if the following is true….
God does not exist + background info =entails⇒ OM does not exist
…then the first premise is true, and to think otherwise is to misunderstand the meaning of the first premise.

Now suppose we know the second premise to be false, i.e. OM does not exist is part of our background info. Then the first premise would be true because we’d get this:
God does not exist + background info

    =entails⇒ God does not exist and OM does not exist

    =entails⇒ OM does not exist
And thus the following entailment would be true:
God does not exist + background info =entails⇒ OM does not exist
Which would mean that the first premise is true. Once we accept OM does not exist as part of our background info, it inevitably leads to the above entailment and thus to the first premise. Thus it is logically impossible for both premises to be false, because the falsity of the second premise (OM does not exist) entails the truth of the first premise.

It is also worth noting that God, as traditionally conceived, entails the existence of objective moral values; God is morally good, and is good independently of whether humans believe him to be so, e.g. God was morally good prior to humans existing. Thus, God entails objective morality existing.

Conclusion



Whether we should believe an if-then statement often depends on the background information we possess, e.g. If it rained heavily in the last five minutes, then Sam’s car is wet depends on factors like whether Sam’s car is in a garage. Similarly, when interpreted correctly the first premise is saying that given the facts of the real world we are in, it is not the case that OM exists if God does not exist. Thus if you believe the following entailment to be true…
God does not exist + background info =entails⇒ OM does not exist
…then you believe If God does not exist, then OM does not exist is true, and to think otherwise is to misunderstand the meaning of the first premise. So if you’re an atheist who denies moral objectivism (and thus has OM does not exist as part of their background info) you accept the first premise, and to think otherwise is to misunderstand what the first premise means. In contrast, if God (a being who is morally good independently of human opinion) exists, objective morality exists.

Once we accept the falsity of the second premise (OM does not exist) as part of our background info, it inevitably leads to the above entailment and thus to the first premise. It is impossible for both premises to be false because the falsity of the second premise entails the truth of the first premise. All that is a bit rough, so if you want a rigorous formal proof for the logical impossibility of both premises I recommend reading part 2 of my introductory logic series.


[1] A few examples:
  1. Adams, Robert M. The Virtue of Faith (New York: Oxford University Press, 1987), p. 105.
  2. Craig, William Lane. Reasonable Faith, Third Edition (Wheaton, Illinois: Crossway Books, 2008), p. 173.
  3. Peter Byrne’s article on the moral argument that used to be part of the Stanford Encyclopedia of Philosophy.
It is also worth considering that the Oxford Dictionary of English lists this as one of the definitions of objectivism, “[PHILOSOPHY] the belief that certain things, especially moral truths, exist independently of human knowledge or perception of them.” Thus on this definition moral objectivism would be the belief that moral truths exist independently of human knowledge or perception of them.

2 comments:

  1. The views of modern society regarding religion, and specifically Christianity, are in a state of great flux. Beliefs that were once sacrosanct are now being called into question. Is the day soon coming when the majority of people in society will view "the Holy Bible" as immoral and evil?

    Imagine if your grade schooler brings home a few books from the school library with these titles:

    1. Giving the Death Sentence to People who eat Forbidden Fruit

    2. Drowning Millions of Children for the Crimes of their Parents

    3. How to Murder First Born Children in their Beds

    4. The Genocidal Annihilation of Evil Foreign Peoples is Justifiable

    You would be horrified that your local school would allow such books in a library for children, wouldn't you? But yet fundamentalist Christians would love to have the Holy Bible in the same library and would not bat an eye at the bloody, barbaric violence and twisted justifications for that violence and immoral behavior contained therein.

    "Oh but that was in another Era of time. It is a mystery why it was necessary for God to do these shocking acts, but we must simply accept by faith that God had good, moral reasons for his actions in the Old Testament."

    Ok...so we will sweep all that barbaric behavior under the rug because Jesus has changed everything. All that bloody violence is no longer necessary because Jesus has ushered in the Era of Grace. We now are to love our neighbor as ourselves...not slaughter him in righteous anger.

    But there is one little problem: Slavery.

    I don't see how putting shackles around the neck, ankles, and wrists of your neighbor and calling him your property is in any way, shape, or form "loving your neighbor as yourself". And I also don't see why a loving, just, Jesus would not have condemned this evil institution, which he did not, nor why the Apostle Paul would condone it, which he very much did.

    Any book that condones slavery is evil and should not be in any school library...nor on your child's nightstand.

    https://www.youtube.com/watch?v=-i3mX0YRrjM

    ReplyDelete