Program / Course 14: Arguments for the Existence of God / Lesson 6.1
What you will learn
- Distinguish the main forms of the moral argument.
- State Kant’s postulate of God, C. S. Lewis’s argument from the moral law and a contemporary argument from moral facts.
- Identify the premise each form most depends on.
- Explain what a moral argument would show even if it succeeded.
The big idea
Moral arguments for God reason from some feature of morality, such as objective moral duties, moral knowledge or the hope that goodness is rewarded, to the claim that God exists. Kant argued that morality requires belief in God as a practical postulate. C. S. Lewis argued from the sense of right and wrong that seems to come from beyond human opinion. Contemporary philosophers argue that objective moral facts are best explained by a good God. Critics say that morality can be grounded without God.
Key terms
- Moral realism
- The view that there are objective moral facts that are true whatever anyone thinks.
- Moral law
- In Lewis’s usage, the sense of right and wrong that people appeal to when they judge each other, which he argues is not mere custom.
- Postulate of practical reason
- In Kant, a belief that is not proved but that reason must assume in order for morality to make sense.
- Highest good
- In Kant, the union of virtue with happiness proportioned to it.
- Moral anti-realism
- The view that there are no objective moral facts, so that moral claims express attitudes, conventions or feelings.
- Best explanation
- A way of arguing that a hypothesis is supported because it explains the evidence better than rivals.
- Prescriptive
- Telling how things ought to be, as opposed to describing how they are.
Background
Moral arguments take several shapes. The oldest idea, found in Scripture, is that God is the lawgiver and judge (Romans 2:14 and 15 speaks of a law written in the heart). In the eighteenth century Kant developed a different form, and in the twentieth century C. S. Lewis popularized another in Mere Christianity, which began as radio talks during the Second World War. Since the 1980s philosophers such as Robert Adams, William Alston, Linda Zagzebski, Paul Copan, Mark Linville and David Baggett have defended other forms.
A feature of all of them is that they begin from something many people think they know, such as that torturing children for fun is wrong, and ask what that knowledge presupposes.
Step-by-step explanation
Step 1: Kant’s form
Kant held that the existence of God cannot be proved by theoretical reason. But he argued that morality commands people to seek the highest good, in which virtue and happiness go together. People cannot bring this about by their own power, because nature does not reward virtue as such. So reason, to make sense of its own moral demand, must postulate a God who can unite virtue with happiness. This is a claim about what a rational moral agent needs to believe, not a proof that God exists.
Step 2: Lewis’s form
Lewis begins from the way people quarrel. They appeal to a standard of fair play that they expect the other to know. This standard is not a mere instinct, because people can judge between instincts, nor a social convention, because people appeal to it to criticize societies. So there is a law of right and wrong that people did not make. Lewis then argues that behind the law there is something that is more like a mind than anything else known. The argument is a sketch, not a full philosophical treatment, and Lewis presents it as the first step on a path to Christianity.
Step 3: Contemporary forms
One contemporary argument reads: 1. If God does not exist, there are no objective moral values and duties. 2. There are objective moral values and duties. 3. Therefore God exists. Craig defends this form. Another argument, from Adams and Zagzebski, holds that goodness is best explained by identifying it with God or the likeness of God. A third argument, from moral knowledge, holds that the human sense of moral truth is best explained if people were designed to know it.
These forms differ in their strength. The first is deductive and depends on the claim that morality needs God. The others are arguments to the best explanation.
Step 4: The premise that carries the weight
In every form, the premise that morality needs God, or is best explained by God, is the one that the opponent denies. The opponent says that morality can stand on its own: on human nature, on reason, on social agreement or on necessary truths. Lesson 6.2 examines these replies.
Step 5: What the argument would show
A successful moral argument would show that there is a source of moral value who is good and who commands or grounds duties. This is closer to the God of the Bible than the conclusions of the cosmological arguments, because it concerns character. But it would not show the Trinity or the incarnation. It would also leave room for debates about which religion best describes this source.
- What is the strongest example you know of an act that is plainly wrong?
- Does that sense of wrongness need an explanation?
- Is Kant’s postulate an argument that God exists, or an argument that people should hope so?
- What does Lewis mean by saying people did not invent the moral law?
- Can a person be good without believing in God? What does your answer imply for the argument?
- Which form of the argument seems strongest to you?
Examples
The quarrel
Lewis notes that someone whose seat is taken by another says, you got there first, or the speaker was in it first. They appeal to a standard both are expected to know. He argues that such appeals show a shared sense of fairness that is not a matter of taste. Critics say a shared sense does not show its source.
The unrewarded just man
A person lives honestly, gives away what he has and dies poor and forgotten. Kant says that unless there is a being who can reward virtue, the moral life ends in a world that does not match what morality hopes for. Critics reply that virtue may be its own reward.
Nuremberg
At the Nuremberg trials, the accused argued that they had obeyed the laws of their country. The court judged that some acts are wrong whatever the law says. Defenders of the argument say this assumes a standard above human law. Critics say it assumes only a standard shared by humane people.
Different perspectives
Catholic
Catholic teaching holds that there is a natural law written in the human heart, knowable by reason, and that God is its source (Catechism, paragraphs 1954 to 1960). The Church sees conscience as a witness to God. Many Catholic philosophers, in the tradition of Aquinas, defend moral arguments in the form of natural law.
Orthodox
Orthodox theology teaches that human beings are made in God’s image and that conscience witnesses to God. It tends to speak of morality as part of a life of communion with God, not as a set of facts needing a metaphysical ground. Orthodox writers are less concerned with the argument form.
Protestant
Protestants have drawn on Romans 2 and the conscience. Lewis, an Anglican, made the argument popular. Calvin spoke of a seed of religion and a sense of right in all. Reformed philosophers like Plantinga hold that moral knowledge, like belief in God, is properly basic. Barth rejected moral arguments as detached from revelation.
Philosophical views
Kant, a Lutheran by upbringing and a critic of traditional proofs, offered the postulate form. In the twentieth century many philosophers, believing and unbelieving, took moral realism seriously, and the question of its basis became a lively one in philosophy.
Skeptical views
Skeptics say that moral claims can be grounded in human well-being, reason or evolutionary history, or can be treated as expressions of attitudes. They add that even if morality needs a ground, it does not follow that the ground is a God. Some, like J. L. Mackie, argued that objective moral values would be strange entities, which counts against realism itself.
Why it matters
Moral arguments appeal to what many people hold most firmly. They invite a student to examine his own moral convictions and ask what, if anything, they presuppose. They also show a different style of argument, from value, in contrast to the arguments from the existence of the world.
Common misunderstandings
Misunderstanding: The moral argument says atheists cannot be good.
Correction: The argument concerns the basis of moral truth, not whether unbelievers behave well. Defenders say plainly that atheists can know and do good.
Misunderstanding: Kant proved God exists by morality.
Correction: Kant said reason must postulate God for the moral life, but he denied that this is theoretical proof.
Misunderstanding: Lewis presented a complete philosophical proof.
Correction: He offered a popular sketch intended as a first step. Philosophers who defend moral arguments state them more carefully.
Misunderstanding: Without God anything is permitted.
Correction: This slogan, from Dostoevsky’s characters, expresses a worry, not an established fact. Whether morality needs God is the question, not the answer.
Knowledge check
What is Kant’s moral argument?
Kant held that morality commands the pursuit of the highest good, the union of virtue and happiness. Nature does not guarantee this, and humans cannot secure it alone. So reason must postulate a God who can unite virtue with happiness. This is a claim about what practical reason requires, not a theoretical proof.
How does Lewis argue from the moral law?
He notes that people appeal to a standard of fair play when they quarrel. The standard is not instinct or convention, since people use it to judge both. So there is a moral law that people did not make. Behind it, he suggests, is something more like a mind. He presents this as a sketch and a first step.
State a contemporary moral argument.
If God does not exist, there are no objective moral values and duties. There are objective moral values and duties. So God exists. The argument is valid, and the debate turns on the first premise, which critics deny by offering grounds for morality without God, and on the second, which some anti-realists deny.
What would a successful moral argument show?
It would show a good source of moral value who grounds duties. This is closer to the biblical God than a first cause because it concerns character. It would not establish the Trinity, the incarnation or any particular religion, so it would be one step in a wider case.
Think it through
- Which of yhuman moral convictions is the most certain? Where does that certainty come from?
- Does the existence of moral disagreement count against moral realism?
- What is lost if morality is only a human convention?
- How should a believer respond to a good atheist?
Independent assignment
Your strongest moral conviction
In your own notebook, write 350 to 500 words. Choose one moral conviction you are very sure of. Explain why you hold it, and what, if anything, you think it presupposes about the world. Then write the best objection to the claim that it points to God, and your reply. Do not send this to anyone.
Further study
- Stanford Encyclopedia of Philosophy, Moral Arguments for the Existence of God Read the sections on Kant, Lewis and the contemporary forms.
- C. S. Lewis, Mere Christianity Read Book 1, chapters 1 to 4.
- Stanford Encyclopedia of Philosophy, The Natural Law Tradition in Ethics Read the introduction for the tradition of natural law.
- William Lane Craig, Reasonable Faith: Christian Truth and Apologetics Read the defender’s statement of the moral argument.
- Romans 2 Verses 14 and 15 speak of the law written in the heart.
- Micah 6 Verse 8 says what the Lord requires.