The lecture opens the Justice course by deliberately refusing to begin where most people expect—no definitions of justice, no big speeches about rights, no list of legal principles. Instead, it drags the audience straight into moral emergencies that feel like traps, because every option carries blood on it. The point is simple but uncomfortable: we all walk around with strong moral instincts, yet we rarely test them until a situation forces us to choose under pressure. The professor uses the trolley problem to expose the hidden logic behind our gut reactions. In the first version, you are the driver of a runaway trolley headed toward five workers, and you can pull a lever to divert it onto a side track where it will kill one worker instead. Most people say they would pull the lever. That response seems to come from a results-first instinct: one death is horrific, but letting five people die when you could prevent it feels worse. The lecture emphasizes that many students feel confident here—not because they’ve studied ethics, but because the situation looks like a clean trade: fewer deaths is better.
Then the lecture repeats the same numbers but changes the method, and that tiny change blows up the confidence people just had. Now you are on a bridge above the track, watching the trolley race toward five workers, and the only way to stop it is to push a very large man off the bridge so his body blocks the trolley. One death would still save five. Yet most people refuse. The professor doesn’t treat this as a weird inconsistency to laugh off—he treats it like evidence that moral judgment isn’t only arithmetic. When the “save five” option requires you to directly use someone as a tool, many people suddenly feel it’s not just tragic but morally forbidden. The lecture uses this shift to reveal what the course is really about: the tension between outcomes and principles, between saving the most lives and refusing to commit certain acts even if they would improve the final result.
To show that this isn’t just a classroom game, the lecture moves into medical dilemmas. An emergency room doctor must choose between saving one severely injured patient or five moderately injured ones; many people again lean toward saving five, which strengthens the idea that consequences matter. But then the transplant scenario appears: a surgeon could kill one healthy person to harvest organs and save five dying patients. Almost everyone rejects this. The lecture uses the audience’s reactions to map the moral boundary people seem to draw: saving more lives feels right until it requires intentionally killing an innocent person as a means. By the end of Part 1, the lecture has achieved its first goal—making you realize that your moral intuitions are powerful, but they’re not automatically consistent, and you can’t understand justice without confronting why you switch rules depending on how the harm is caused.
Part 2
After the dilemmas expose the conflict, the lecture gives names to the two moral engines fighting underneath our decisions. One engine is consequentialism, the idea that the morality of an action depends on its results, so the “right” choice is the one that maximizes overall good or minimizes overall harm. This is the logic that makes the lever-pull feel obvious: one death instead of five appears like a morally responsible trade. The other engine is categorical moral reasoning, the idea that morality is anchored in duties, rights, and constraints—meaning some actions are wrong in themselves even if they produce better outcomes. This is the instinct many people feel in the bridge and transplant scenarios: pushing a man or killing a healthy patient feels like crossing a moral line that cannot be washed clean by pointing to the number of lives saved.
From there, the lecture introduces utilitarianism as a powerful form of consequentialism associated with Jeremy Bentham (and later John Stuart Mill). Utilitarian thinking is attractive because it promises clarity: we can judge actions and policies by how much happiness or “utility” they produce for the greatest number. That clarity matters in politics and law, where choices always affect many people at once. But the lecture also makes clear why utilitarianism scares people: if outcomes are all that matter, then almost any act could be justified if it increases total welfare. The transplant case becomes the emotional warning sign—people instinctively resist a world where a person can be killed simply because their death would benefit more others. That resistance suggests that we don’t just care about totals; we care about how individuals are treated, whether they’re respected as persons rather than reduced to tools or resources.
On the other side, the lecture previews Immanuel Kant and the idea of a categorical imperative—a moral law that binds regardless of outcomes. The lecture doesn’t fully dive into Kant yet, but it sets up what the students will soon face: a view where using someone merely as a means is a moral failure even if it saves many lives. This is why the course doesn’t stay in abstract puzzles. The lecture hints that real political issues—rights, equality, free speech, military conscription, punishment—are basically trolley problems wearing suits. If you’re outcome-driven, you may accept harsh tradeoffs for larger benefits. If you’re duty-driven, you may refuse tradeoffs even when refusal leads to suffering. The lecture frames the course as learning to argue honestly about those tradeoffs, instead of hiding behind slogans like “common sense” or “it’s obvious.” Moral philosophy, in this view, is the practice of dragging your instincts into the open and forcing them to survive the pressure of reasons.
Part 3
The lecture’s final punch is to prove that this isn’t just hypothetical reasoning by bringing in a real case: Queen v. Dudley and Stephens. Here, the trolley problem stops being a diagram and becomes a courtroom nightmare. After a shipwreck, four sailors are stranded without food or water. As starvation reaches the point of death, Dudley and Stephens kill the cabin boy, Richard Parker, and cannibalize him to survive. When they are rescued, they are put on trial for murder. Their defense is necessity: they argue that the killing was required for survival, and without it more people might have died. The lecture uses this case to force the audience into the harshest question yet: if your moral rule is “save the most lives,” are you prepared to say this killing was justified? And if you refuse to justify it, what principle are you relying on that survives even at the edge of death?
The class discussion in the lecture tests two “escape hatches” that people often reach for when an act feels wrong but the situation feels desperate: fair procedure and consent. Some students consider whether a lottery would have made it morally acceptable—if everyone had equal chance of being chosen, would the killing become fair, and therefore permissible? The lecture pushes this hard because it reveals a deeper issue: fairness of procedure might reduce one kind of injustice (favoritism), but it may not change the basic moral status of killing an innocent person. Then consent enters: what if the cabin boy had agreed? The lecture challenges whether consent can ever be truly free under extreme coercion—when the alternative is starvation, “agreement” can become a distorted form of surrender. Even beyond coercion, the lecture raises the unsettling thought that some actions might remain wrong even with consent, because the moral issue is not only “did the victim agree?” but “what kind of act are we becoming willing to do to another human being?”
By ending with this case, the lecture makes the course’s mission impossible to ignore: justice is not only about what the law says, but about the moral reasoning we use to defend what the law should allow or forbid. The trolley problem shows that our instincts change with framing; the medical cases show that “saving more” doesn’t automatically justify “doing anything”; Dudley and Stephens shows that real life will eventually corner societies into decisions that feel morally dirty no matter what they choose. The lecture closes by warning students that philosophy is risky because it can destabilize beliefs they thought were solid—yet it’s also unavoidable, because everyday life and political life constantly demand moral choices. The course, as introduced here, is an invitation to face those choices with clarity: to understand why you believe what you believe, what your beliefs imply when pushed to the extreme, and whether you can live with the justice you claim to defend.
