Michael Munger on How Adam Smith Solved the Trolley Problem

Episode Summary

Executive Summary: Russ Roberts and Michael Munger examine the trolley problem through Adam Smith’s moral philosophy, arguing that people distinguish sharply between allowing harm and actively causing it. Munger shows Smith’s “impartial spectator” explains why we may feel more distress about personal loss than distant suffering, yet still refuse to sacrifice others for ourselves. The discussion connects philosophy to abortion, war, and autonomous cars, and ends with a defense of commercial society as compatible with moral norms.

Main Topics: The trolley problem and double effect (Priority: 5/5): Munger reviews Philippa Foot’s formulation and the doctrine of double effect: people judge causing harm differently from allowing harm, even when outcomes are similar. Adam Smith’s moral psychology (Priority: 5/5): Smith’s Theory of Moral Sentiments is presented as a precursor to the trolley problem, explaining how the impartial spectator, conscience, and self-governance shape moral judgment. Preference reversal between feeling and action (Priority: 4/5): The conversation highlights Smith’s puzzle: we may care more emotionally about ourselves or our little finger, but when acting, we usually refuse to harm many others for that benefit. Applications to war and public policy (Priority: 4/5): The atomic bomb, firebombing, and WWII casualty estimates are used to show how real-world decisions resemble trolley dilemmas and how intention changes moral framing. Limits of hypotheticals and survey ethics (Priority: 3/5): Roberts and Munger critique simplistic trolley-problem survey conclusions, arguing that real-world uncertainty, resistance, and unintended consequences are often ignored. Capitalism and moral character (Priority: 3/5): They debate whether commercial society coarsens people. Munger argues Smith thought markets can coexist with, and sometimes reinforce, moral sentiments rather than erase them.

Key Arguments: Smith’s puzzle is not about what is emotionally upsetting; it is about why people would refuse to act on self-preference when action would harm others. The doctrine of double effect captures a moral distinction between foreseeing harm and intending harm; this distinction underlies much of trolley-problem intuition. Munger argues Smith’s “impartial spectator” and internalized conscience explain why people often choose the greater good over private advantage. Roberts and Munger both stress that many trolley hypotheticals assume certainty and ignore the possibility of resistance or alternate outcomes, making survey results less reliable. The atomic bomb debate is framed as a real-world trolley problem: intentional killing of civilians versus a military invasion with potentially far larger casualties. Smith’s view of commercial society is not that markets alone solve morality, but that markets can operate alongside norms of propriety, gratitude, and self-command. Capitalism is not inherently coarsening; compared with command economies, markets may actually encourage perspective-taking and mutual accommodation.

Data Points: EconTalk episode count for Michael Munger: 46th appearance - Russ Roberts notes this is Munger’s 46th appearance on EconTalk. Year of Philippa Foot article: 1967 - Munger cites Foot’s original paper introducing the tram problem. Adam Smith’s birth tercentenary: 300th anniversary - Roberts notes the conversation occurs during Smith’s 300th birthday year. WWII casualty estimate for Operation Katsugo: At least 2 million soldiers and as many as 50 million civilians - Munger reports Japanese estimates for a mainland defense plan if the U.S. invaded. U.S. Okinawa casualties: 25,000 dead; nearly 100,000 wounded or put out of action - Used to illustrate expected costs of a mainland invasion. Japanese Okinawa deaths: 200,000 - Compared with projected mainland war casualties. Estimated U.S. invasion casualties: Up to 1 million U.S. soldiers - Munger cites estimates used in the atomic bomb decision discussion. Hiroshima and Nagasaki deaths: About 200,000 - Roberts references a quick Google estimate of immediate deaths from the bombings. Tokyo firebombing deaths: About 100,000 in a single night - Roberts cites the firebombing of Tokyo as another mass-casualty intentional attack. Dresden firebombing deaths: 25,000 - Roberts mentions Dresden as another example of civilian bombing.

Pivotal Quotes: "It is reason, principle, conscience, the inhabitant of the breast, the man within, the great judge and arbiter of our conduct." — Michael Munger: Munger reads Adam Smith to explain why people refrain from sacrificing others for self-benefit. "Human nature startles with horror at the thought." — Michael Munger: Smith’s rejection of sacrificing 100 million lives to save one’s little finger. "There is a difference between allowing a harm and causing a harm. There’s a difference between allowing a death and killing." — Russ Roberts: Roberts summarizes the core moral distinction that links Foot’s tram problem to Smith’s analysis.

Implications: The episode suggests moral judgment depends on intention, agency, and internalized norms—not just outcomes. For policy and ethics, it warns against naive utilitarianism and argues markets can coexist with, and even reinforce, moral character.