A Further Difficulty in Naturalism

Big idea

Summary

Lewis extends the argument of Chapter 3 from reasoning to moral judgment. Just as reasoning claims to track real logical relations rather than being merely caused, our judgments that something 'ought' to be done, or that a certain act is genuinely good or evil, claim to track a real moral truth rather than being merely the byproduct of upbringing, instinct, or social conditioning. If Naturalism is true and every event is simply the non-rational product of prior causes, then moral convictions are reduced to the same status as any other conditioned reflex, and the distinction between a genuinely good act and one we merely feel approval toward collapses.

He anticipates the objection that moral feelings could still be useful survival mechanisms, shaped by evolution, even if they don't track any real moral order. Lewis's reply parallels his answer about reason: usefulness for survival is a different thing from truth, and if our moral sense is explained away as 'merely' useful rather than as tracking something real, we lose any basis for saying some moral claims — including claims a Naturalist himself relies on, such as that intellectual honesty is good or that cruelty is wrong — are actually true rather than simply adaptive.

As with reasoning, Lewis is not arguing that natural causes play no role in how moral beliefs arise in any individual case; he is arguing that a thoroughgoing Naturalism, which treats every event as merely caused and nothing as a genuine rational or moral insight, cannot in the end account for the authority we all, including committed Naturalists, actually grant to at least some moral judgments.

Key points

• The parallel to Chapter 3: just as reasoning claims to track logical truth, moral judgment claims to track real value, and Naturalism struggles to explain either as more than conditioned reflex.
• If moral convictions are 'merely' caused by upbringing or evolutionary usefulness, we lose grounds for calling any of them actually true rather than simply useful or adaptive.
• This difficulty applies even to convictions Naturalists themselves rely on, such as that honesty is good — convictions a strict Naturalism cannot fully underwrite.
• Lewis is not denying natural causes shape how individuals come to hold moral beliefs; he is denying that this fact alone can account for morality's felt authority.

Illustrations & analogies

• The evolutionary explanation of moral feeling as a 'useful' survival trait is treated the same way Lewis treats explanations of reason as 'useful': usefulness for survival and truth are shown to be two different things that a strict Naturalism keeps confusing.

For reflection and discussion

1. Lewis suggests that treating morality as 'merely' a product of evolution or upbringing undercuts its authority. Do you agree that usefulness and truth are really different things here?
2. Can you think of a moral conviction you hold that you would still call true even if it turned out not to have offered any survival advantage?