[Perusing a plethora of unpublished pupil projects on this topic inspires my proverbial pen. I’ll be checking back often to update and improve on this post so feel free to share you thoughts as you might inspire future improvements.]
DIAGNOSING THE QUESTION: “CAN MAN BE GOOD WITHOUT GOD”
On the topic of whether man can be good without God, several readings arise.
1. “Man” could mean (a) individuals, (b) groups, or (c) mankind as a whole.
2. “Can” could mean (a) practically able, (b) logically possible, (c) metaphysically possible
3. “Good” could mean (a) moral goodness, (b) theological goodness–i.e., “no man is good save God alone,” (c) axiological goodness–any values termed “good,” (d) practical/instrumental/conditional goodness–i.e., conditional imperatives, in Kantian terms, (e) self-sufficiency/competency (i.e., “I don’t need salt for my food, I’m good, thank’s for offering.”)
4. “Without God” could mean (a) without God’s existing or (b) without belief in God.
With these variant readings, there are 90 total combinations (3 x 3 x 5 x 2). For simplicity’s sake, we can recast this problem in terms of a single, clarified question, “Is it practically possible for people (individual or in groups) to be morally good if there were no God?” This recast question is what I mean when I ask, “Can man be good without God?” and that is the question I’ll be addressing in this essay. Before getting ahead of ourselves, first let us curtail some likely distractions.
This is not a question of whether some non-theists can be broadly “good” without God-belief. (4.b.). Clearly non-theists can be law-abiding, charitable, just, or otherwise “good” in a popular, conventional, and well-agreed-upon sense. This sense is trivial, I contend, if it turns out that the only way non-theists can be “good” is on borrowed currency from the moral systems of theism (i.e., any morally weighted belief system with a god in it). From a theistic worldview, one can expect that non-believers will have some common access to the same natural laws that believers have, so theists should expect nontheists to be somehow “good,” wanting to avoid moral guilt and shame, to be justified in their actions, and feel forgiven and reconciled in their relationships. It may prove important, however, to address a form of this question later. God-belief does have a relevant connection to God’s existence, and morality can be affected. God-belief is an epistemic position. It is a knowledge claim. But believing in God is not also “knowing the good” unless there is a God who himself defines “the good.” If God were the only means to ground goodness but there were no God, then the theists still might be the more “moral” for believing and acting on their imagined God’s moral code.
Put another way, if God did not exist, and if that fact somehow undermined morality, then it could follow that morality is most common/strong among deluded theists (i.e., believing in God despite his non-existence). In that event, the need for a moral system could force humanity to invent God, even if he did not exist, lest our amoral beastly nature overcome us. Evolutionary naturalism and reductive materialism, for example, readily tell us that we are products of forces outside ourselves, we are mere animals, we are brute nature, we are not really free at all–what then is to stop us from acting like the animals that we are? It could be that an imagined God is needed if only to protect us from ourselves. I don’t think this scenario is adequate but I do believe it is closer to the truth than is any self-content non-theistic ethics.
next, this question is not about whether human beings can be morally perfect (i.e., theological goodness). Even if people could be morally perfect, the claimants to that status are either too few or too suspect to prove that perfection is possible for others. Perhaps Jesus fit the bill, but even from a Christian perspective he’s a bit exceptional and doesn’t “prove” that anyone else could be morally perfect.
DISSECTING THE PROBLEM
With the questioned diagnosed and recast, we can dissect it to discover its component parts. The effort is to study the problem en route to a solution. Endless analysis is mere paralysis. But subjects like this are weighty and involved, needing at least some analysis. It’s too complex for simplistic, rushed, or superficial treatments. Recall that the question at issue is: “Is it practically possible for people to be morally good if there were no God?” Here several facets present themselves.
1) The problem of moral language–how does moral language “mean”? Do moral claims signify, emote, obscure, or what?
2) The problem of moral knowledge–how might one access a moral idea? how might moral knowledge happen, if at all?
3) The problem of moral grounding–what would make a moral fact factual? If there are no moral facts, then what kind of a thing is morality, and what makes it what it is?
4) The problem of moral motivations–what is the nature of moral incentive?
5) The problem of moral psychology–what is the nature of a moral agent, or a moral mind?
I have no intentions to do a book-length treatment of the subject, at least, not here. So I can only pick one or two of these and focus on them. In particular, I want to focus on the problem of moral grounding.
Briefly stated, the problem of moral grounding, “What makes good ‘good’?” What is that something which makes an object a moral object? The question is interesting because we often think or assume that there are moral facts about our world, and these are either true in themselves, made true by something else, or they are not true at all. If they are not true, then they are either false or meaningless.
These can be listed as:
What makes a good thing ‘good’?
* Intrinsic Moral Realism: The thing itself
* Extrinsic Moral Realism: Something else
* Moral Irrealism (weak form): Nothing, “goodness” is meaningful but false in all cases.
* Moral Irrealism (strong form): Nothing, goodness is meaningless and not even false, much less true.
These last two options might be confusing. For moral language to “mean” something it would have to “point,” “denote,” “convey,” etc. some other thing besides itself such as an idea, a natural fact, or feeling. The symbols and words of language must have content besides themselves if it is to be language at all. Meaningless language is not language. If there were never content for moral language, then moral language would always be meaningless and not really a “language” at all, but more like emotive outbursts like “Ouch!,” “Yikes!,” or “Whoah!.” However, if moral language has content, but always fails that relationship between moral language and its content fail
The question admits two modes of answer: (a) There are moral facts (moral realism) and (b) there are no moral facts (moral irrealism). According to moral realism moral objects exist in reality, so to say, “Rape is evil,” is an expression of some real object.
Intelligent Christian Faith 
You know, it’s when theists say things like calling good in a popular senselike charitable, law abiding and just, trivial, that we atheists start to worry. What is this religious morality that is not covered in the above list? Eating fish on Friday?
There is no doubt we are animals, but I don’t know why you add “mere” in this way. We are clearly exceptional animals will incredible intellect and power. This animal status in no way diminishes the wonder and awe of ourselves or nature. Other animals have morality. Lobsters and beavers mate for life. Most mamals will die in protecting their young. Wolves ostracize, other apes share. Are they also borrowing from theist morality? Or rather, have humans evolved a much more complex and subtle morality along with conscious reflection and thousands of gods?
I didn’t say those kinds of good are trivial, I said the question “Can man be good without God?” is only trivially understood as “Can man ascribe to a sense of ‘goodness’ regardless of what makes that sense ‘good'” is trivial. Its like comparing the builder of the house to the person who moves in and lives there for a week. Whose contribution is more substantial? The person who established that residence or the person who used it thereafter? It is no proof of naturalism to say, ‘We found it, like this. Houses are natural. They are part of nature. Of course we can live in houses without believing in an objective house-builder.”
Worry all you want, but your worry is misplaced.
If we are JUST animals then we have every reason to act like animals. Our popular sense of “act like animals” is admittedly negative . . . for a reason. It is an insult to humanity to think of humans as merely animals. Saying we are “special animals” or “especially fit/adapted animals” or something like that still leaves us dead set within the brutal tooth and claw of evolutionary violence. Evolutionary forces and mechanistic nature is hopelessly ill equipped to explain the profoundly complex phenomenon of morality, the likes of which are so subtle in its interweaving of epistemology and metaphysics that reductivistic naturalism invariably sweeps its ignorance under the rug through so many claims of, “Morality is just altruism,” or “Self-interest can accidentally serve others,” etc. etc. The only point of comparison to distinguish “Nursing one’s young” from “Eating one’s young” is not personal, prescriptive, or judicial at all, but–according to naturalism–it is the amoral mechanistic tendency of nature to kill everything and more slowly kill its fit or fortunate subjects. If eating about 20% of our young were evolutionarily more advantageous than nursing our young, then–by your standard–eating our young would suddenly be moral. At its basis, naturalistic morality looks to be contrived, arbitrary, and amoral.
If we are NOT just/merely animals then we might have reason to think more highly of ourselves and not let brute mechanical forces of nature or animal behavior dictate our behaviors. Put another way, if we are more than mere animals then we would not be coerced by our genes and environment to act deterministically (instead of freely), in the absence of propositional content (like, “Rape IS evil”), intentional attitudes (“I don’t want to rape anyone”), and informed consent (“X would be indistinguishable from rape so I know not to do X”), concerning metaphysically grounded moral principles (overcoming the Is-Ought problem).
I don’t believe for a moment that other animals have morality, not in any objectively real sense comparable to how we humans encounter it. Please prove that animals have morality in any relevant sense to this discussion. From a naturalistic standpoint, animals have behaviors prescribed deterministically by their genes and environment, but you’ll have to show that that somehow equates to morality, because it doesn’t look like that to me.
So you don’t think charity and justice are trivial then, no matter who does them?
I will decline to get into evolutionary psychology. For this discussion I can accept that it makes little sense to speak of animals being moral if they lack a consciousness capable of reflection.
Lets look at the question you raised. I think we can both agree that a good act undertaken by a theist is still “good” if undertaken by a non-theist. You just seem to be saying that the non-theist misses the source of the “goodness”, which you say is a god. The act itself is trivial compared to the source which is God. But then the theist is equally limited in the good she or he is doing. Her good act is also trivial compared to the source. The difference is that the theist recognizes the source.
Until you can convince me that the god exists, I will still look to the individual as the source of the good.
But isn’t it also true that , while we may be missing the true source of our instinct to be good, we atheists can still be good by referring to objective moral values such as limiting suffering and harm and furthering well being and prosperity?