It's all about the deep questions.
Theism: Moral Arguments
Many people who are theists believe that morality simply cannot exist without theism. This opens up another argument for theism. I will argue that not only does the argument fail, but I will also introduce my first argument against theism. I will argue that if one presupposes that objective morality does exist, and if theism entails that God must be the grounding of that morality (both of which theists usually affirm), then theism is false.
The moral argument
1. If theism were not true, then objective morality would not exist.
2. Objective morality does exist.
3. Therefore, theism must be true.
Criticism 1: how do you know objective morality exists anyway?
I currently tentatively hold to Mackie’s Error Theory(largely dependent on whether hypothetical imperatives are really a source of normativity), which holds that all talk of morality and what one ought to do has no plausible basis. The whole discourse is flawed. A full discussion of this would be very lengthy, so I cannot go into the specifics here. Here, I seek only to cast doubt on the grounds by which theists hold that there really is objective morality. After all they are the ones making the existence claim, so they have the burden of proof. Unfortunately, theists don’t have many grounds for making that assertion. Basically, they all amount to a bundle of intuitions. Intuitively, abusing little children is bad. Well, of course I grant that that is intuitively true, but it is a huge leap to say I feel like some things are morally bad (whatever that means, and for whatever reason one picks that meaning as opposed to another) to ascribing your intuitions to the universe in some objective way or by creating magical “categorical imperatives” or “intrinsic values”. All I can criticize is the second premise, since I basically stand by the first one, albeit with some reservations.
Criticism 2: a counter-argument
1. If god was the grounding for morality, morality would not be objective
2. Morality is objective.
3. God is not the grounding for morality.
(one can add two additional premises if one wishes. Whether theism does entail that god is the ground for morality is really a matter for definition, so I’m not really interested in arguing for that)
4. If theism were true, god would be the grounding for morality.
5. Theism is false.
I take it for granted that the theist affirms premise 2. As mentioned, premise 4 is a matter for “definition debate”, which is basically an oxymoron. So, the obvious premise that the theist would criticize would be premise 1. Here I will provide 2 lines of support.
Sub-support 1: Euthyporo dilemma
Does god simply call certain acts morally good because they in fact are good in and of themselves, or does god saying that a certain act is good make it morally good? If the first option is taken, then god is simply a messenger that relays to us what is good and what is bad. This option would not even make god the grounding for morality. If the second option is taken, morality is construed on whims, and hence not objective. God could have easily said “rape is good”, which would make rape, in fact, good. If the theist objects here that god does not call rape good because he has independent reasons for thinking that it is bad, then there would have to be an independent standard to which acts must conform to to be morally good. The grounding of morality would then be the standard, not god. This would fall under option 1. Both options fail to construe god as an objective source of objective morality. The typical theist response is that morality is grounded in gods nature. This doesn’t solve anything, however; it just pushes the problem a step back. Is compassion good because it happens to be a part of God’s nature, or is compassion a part of God’s nature because it is already good?
Sub-Support 2 : Objectivity
The very definition of objective is to be true or false regardless of any person’s attitudes, desires, natures, etc. If this is so, then it is obvious that theistic morality is not objective, for one of theism’s central premises is that god is a personal being. If morality is grounded in a person, namely god, then it can’t be objective. What went wrong here? The theist must be using a different definition of objectivity than usual. Perhaps his definition is something along the lines of: not grounded in any particular human being. Then, in that case, we can ground our morality, objectively, in the nature of some random chimpanzee. So even that definition suffers from problems. Maybe the theist wants it to mean something along the lines of: not grounded in a non-divine person. Well, although it seems a bit contrived, at least it works for the theist. This definition, I’m sure, is absolutely nothing like what people actually mean when they use the word objective though; no non-theist would agree that their theory is the least bit objective. Therefore, it does not impress me at all that this ethical theory, divine command theory, is “pseudo-objective”. Would the theist, then, accept a system of morality grounded in Quetzacoatl as more “in the right direction” than any secular theory such as utilitarianism or virtue ethics? Apparently so. The intellectual hurdles that the theist has to jump through to even get their system of morality off the ground detracts greatly from its respectability as an ethical theory.
Conclusion: Divine command theory, which is the only candidate “god-based morality” has many troubles. In addition to not being objective (in the usual way), it leaves the possibility open that God could have easily commanded rape to be good, because he has absolutely no outside reason to deem it bad. This, in my opinion, is a fatal hurtle for Divine Command theory as a theory of morality.