The moral argument for the existence of God refers to the claim that God is needed to provide a coherent ontological foundation for the existence of objective moral values and duties. The argument can be summarised in the following syllogism:
Premise 1: If God does not exist, then objective moral values and duties do not exist.
Premise 2: Objective moral values and duties do exist.
Conclusion: Therefore, God exists.
Since this is a logically valid syllogism, the atheist, in order to maintain his non-belief in God, must reject at least one of the two Premises. By “objective” morality we mean a system of ethics which universally pertains irrespective of the opinions or tastes of human persons: for example, the holocaust was morally wrong irrespective of what Hitler and the Nazis believed about it, and it would have remained morally wrong even if the Nazis had won World War II and compelled everyone into compliance with their values. This view, known in philosophy as “moral realism,” contrasts with “moral relativism” which maintains that no-one is objectively correct or incorrect with respect to their moral values and judgements.
Most people want to uphold premise 2 of the moral argument. After all, if there are no objective ethics, then who is to say that Hitler was objectively morally wrong? Humans have an intuitive sense of right and wrong. The moral argument requires only that at least some actions are objectively right or wrong (e.g. torturing children for pleasure is objectively morally wrong). Premise 1 relates to the perfect standard against which everything else is measured. God, being the only morally perfect being, is the standard against which all other things are judged. Moreover, in the absence of theism, nobody has been able to conceive of a defensible grounding for moral values.
Moral Argument – An Important Distinction
It is important to bear in mind that the moral argument pertains to the ultimate source of objective moral values and duties (moral ontology) and not how we know what is moral or immoral (moral epistemology) and not 'what we mean' by good/bad or right/wrong (moral semantics). The theistic ethicist maintains that moral values are grounded in the character and nature of God.
Those who are divine command theorists maintain that moral duties are based on what God commands. Philosopher William Lane Craig puts it this way:
“Duty arises in response to an imperative from a competent authority.
For example, if some random person were to tell me to pull my car over, I
would have absolutely no legal obligation to do so. But if a policeman
were to issue such a command, I’d have a legal obligation to obey. The
difference in the two cases lies in the persons who issued the commands:
one is qualified to do so, while the other is not.”
Plato, in his dialogue Euthyphro, presents a fictional dialogue between his philosophical mentor, Socrates, and a character by the name of Euthyphro. Euthyphro explains to Socrates that he has come to lay manslaughter charges against his father, because of his involvement in the death of a worker. This worker himself had killed a slave who had belonged to the family estate. This worker was found dead, gagged, and bound in a ditch. This gives rise to a lengthy dialogue between Euthyphro and Socrates, which eventually leads to the famous “Euthyphro’s Dilemma.” Socrates says, “But I will amend the definition so far as to say that what all the gods hate is impious, and what they love pious or holy; and what some of them love and others hate is both or neither. Shall this be our definition of piety and impiety?” Euthyphro goes on to say “Yes, I should say that what all the gods love is pious and holy, and the opposite which they all hate, impious.” Socrates subsequently inquires of him, “The point which I should first wish to understand is whether the pious or holy is beloved by the gods because it is holy, or holy because it is beloved of the gods.”
The question is posed this way: Is x the right thing to do because God commands it, or does God command it because it is already the right thing to do? I take the former option. Normally, the problem with accepting the horn is that there is a presumption that the commands in question from God are arbitrary (i.e. God could have commanded that we ought to lie). But that's just false. The theist wants to say that God is essentially loving, honest etc., and therefore, in all worlds at which God exists, his commands are going to be consistent with his nature. And therefore, in all worlds, he will disapprove of lying.
Moral Argument – The Shortcomings of Utilitarianism
There are various nontheistic systems of ethics, none of which succeed in providing a robust ontological foundation or objective moral values and duties. One of these systems, popularised recently by Sam Harris in his book The Moral Landscape, is called utilitarianism, and (in its most common formulation) refers to the view that ethics are determined by what constitutes the greatest happiness for the greatest number. One difficulty lies in the fact that it attempts to balance two different scales employed to assess the moral virtue of an action (i.e. the amount of utility produced and the number of people affected). This can often lead to conflicting answers—in some cases an activity might be considered better for a greater number of individuals whereas a different activity might create a greater overall utility. Utilitarians try to maximize with their actions the utility of the long-term consequences of those actions. However, short of possession of omniscience, it is impossible to evaluate the respective long-term results of different activities. Utilitarianism also does not take into account the individual’s intent—Activity X could be done sincerely by an individual who believes that what he is doing will create the maximum utility. But if activity X turns out in the long-term not to produce the desired utility, then his action, under the philosophy of utilitarianism, would be considered less moral than an activity that created more utility.
In conclusion, the moral argument is a robust argument for the existence of God. It is important to distinguish between moral ontology and epistemology when engaging in this debate since these categories are frequently conflated by atheist critics. Humans, being shaped in the image of God, have an intuitive sense of right and wrong. It is not at all clear how the atheist, except at the expense of moral realism, can maintain an objective standard of ethics without such a being as God as his ontological foundation.