There are a fair few problems here. You're saying that you can't have normative ethics without objective morality. But what do you mean by "objective morality"? It's objectively a true fact that (say) most of us think that murder is immoral. Is that what you mean by objective morality? Or is there something more to it than that? You need to specify what it is you're asking for, at least on that score.
If you're asking for "moral facts" and a justification of their existence then I think you'll be disappointed because it's pretty controversial among meta-ethicists whether moral facts exist at all - even among those who believe in objective, normative moral statements. This is, at root, because it's hard to see how you can derive normative imperatives from facts in the first place.
For example: suppose that moral facts exist and suppose that it is an objective moral fact (whatever you think that means) that murder is wrong. Does that give me an imperative not to murder? It's hard to see how it does. To say that
I shouldn't murder isn't really to state a fact in the first place - it is to insist upon a certain way of behaving. How do we derive the
ought of "I shouldn't murder" from the
is of "Murder is wrong"? How do we derive a value from a fact? Considerations such as this seem to me to suggest that "moral facts" are explanatorily useless for basing normative ethics upon. Even if they exist, they don't explain the normativity of ethical values. So why suppose that they even exist at all, let alone that they are
required for normative ethical values?
It seems to me that you're assuming, without argument, some form of cognitivism about moral statements; but of course that is very controversial. I think today that most meta-ethicists would reject simple cognitivism - just as they would also reject the simple non-cogntivism that was all the rage in the 60s, when people thought that "Murder is wrong" translated to a simple non-cognitive expression of disgust at the thought of murder. The problem is how to recognise both the cognitive and the non-cognitive elements of moral statements, and there is no generally accepted theory of how to do this.
As for the question how normative ethics can be derived without God: I'd start by turning that question around and asking what God would add to the equation. You said:
Gogf said:
God helps because religion uses the deity as a source of truth, and therefore justifies the existence of objective morality as flowing from god and our access to it as coming from communication with god.
But that isn't true, because of the Euthyphro problem. In the context of this discussion we can rephrase that problem like this:
Suppose God says that murder is wrong. Now, we can ask: does God say that murder is wrong
because murder is wrong? Or is murder wrong
because God says that murder is wrong? Suppose we go for the first of these. In that case, the wrongness of murder does not derive from God at all; rather, murder is wrong for some other reason, and God's prescription is based upon that reason. So appealing to God doesn't explain the wrongness of murder.
Suppose we take the second option, then, and say that murder is wrong simply because God says it is. Well then, why does God say it's wrong? Does he do so arbitrarily? Might he just as well have said that murder is right, or even ordered us to murder? If this is so, then God's decisions are arbitrary and he is no better than a tyrant whose whim is law. In fact classical theists have always thought that God is rational and good: everything he does, he does for a reason, and he always does the best possible thing that he can. If that is so, then he must forbid murder (as opposed to command it) for a reason, and it must be good that he forbids it (rather than commands it). But if that is so, and there is a
good reason for his forbidding rather than commanding murder, then that reason (whatever it may be) is what makes murder wrong rather than right. And so, once again we find that the explanation of morality cannot lie in God's command, but in something else, which God's command merely reflects.
Sensible theists such as Leibniz have always been well aware of this and avoided any divine command theory as a result.
There is a second reason why God doesn't work as a grounding for morality, and that is the same reason I gave at the start, which is that it is hard to see how you can derive normative strictures from plain facts at all, whatever those facts may be. Suppose that we say that murder is wrong because God says so. Does that give me any
moral reason not to murder? Of course it may give me some reason not to murder (to avoid divine punishment) but that is no different in kind from refraining from murder because of fear of the police; it's not a
moral reason. It seems to me that saying "God forbids murder" is as motivationally inert as "Murder is wrong" in the first place. It adds nothing.
So as I see it, appealing to God adds absolutely nothing in meta-ethics. Theists, atheists, and everyone else are in exactly the same boat when it comes to explaining what moral statements are and why they are normative, if they are.
So how can one derive normative morality at all? Well, as you no doubt know, there are lots of possible ways. One answer, or non-answer if you prefer, is that you just can't. Moore's famous "open question" argument purports to show this: take any (natural) factual claim about a certain thing or action that you like, and it remains an open question whether that thing is
good. He concludes that "goodness" is a basic and non-natural property. It isn't based upon anything else, it just is. If that's the case, then trying to find a basis for normative morality is just wrong-footed from the start; it can't be done because goodness (or rightness, if you prefer) is basic and not based on anything. It just is.
It seems to me that utilitarianism gives a sensible starting point for moral reasoning, but of course it still assumes that (something like) "bringing about the most happiness" is the right thing to do; it doesn't explain
why that is the right thing to do or tell us, indeed, what "right" means. But that's because it's an ethical theory, not a meta-ethical theory. It seems to me that you're asking for both of these at the same time. I think that a utilitarian could consistently say something like the intuition that it is right to bring about the most happiness is basic and cannot be grounded on anything else, and she can say that this can be the basis of normative morality without having to explain what "X is right" actually means. After all, the latter is the task of philosophers of language, not of ethicists.
I would also say that virtue ethics seems to me to offer a plausible way to ground ethics (of some kind) in natural facts, namely the facts about what makes human beings flourish. Virtue ethics focuses on the character habits that are most conducive to a happy life, and recommends actions on the basis of whether they bring about those habits or not. Of course, once again we hit the fundamental distinction between doing things for a moral reason and doing them for a non-moral reason. If my choosing not to murder someone solely because I'm scared of getting caught is a non-moral reason for refraining from murder, then so too, my choosing to inculcate a generous character in myself because it will lead to a happier life for me is a non-moral reason too, and it is hard to see why there is a
moral imperative upon me to do so. But then a virtue ethicist might simply argue that thinking in terms of moral imperatives of that kind is the wrong way to think about it in the first place. It is hard to find such imperatives in the work of the great virtue ethicists of the past such as Aristotle and Aquinas; these were not the questions that interested them.
Anyway, you should start your search for answers to these questions
here, noting that other than the discussion of the Euthyphro problem at the start, God is not mentioned, for the good reason that God is irrelevant to the question. So you can treat it as an atheistic approach to the question if you want.
Akka said:
Because morality is about acting good or bad, and the Golden Rule is exactly that : telling you if what you do is good or bad.
I think you've misunderstood what he's after: he wants to know why atheists think that their moral systems
do tell you what's good or bad. Citing the Golden Rule (or any other moral precept) doesn't answer that question.
Why is it right to do to others as I'd have them do to me? What does it mean to say that such actions are "right" at all?
Also, I agree entirely with Orange Seeds that the "Golden Rule" is a very poor moral compass anyway, for the reasons already given, and this is why it does not, in fact, appear in most rigorous ethical systems. I'd dispute the claim that it appears in most non-rigorous ones, in fact; one can find it in various religions only by interpreting it so loosely that a wide variety of rather different moral strictures are all considered to be equivalent.