The Trolley Problem, or Would You Throw the Fat Guy Off the Bridge?

A Philosophical Conundrum


By Thomas Cathcart

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A trolley is careering out of control. Up ahead are five workers; on a spur to the right stands a lone individual. You, a bystander, happen to be standing next to a switch that could divert the trolley, which would save the five, but sacrifice the one—do you pull it? Or say you’re watching from an overpass. The only way to save the workers is to drop a heavy object in the trolley’s path. And you’re standing next to a really fat man….

This ethical conundrum—based on British philosopher Philippa Foot’s 1967 thought experiment—has inspired decades of lively argument around the world. Now Thomas Cathcart, coauthor of the New York Times bestseller Plato and a Platypus Walk into a Bar, brings his sharp intelligence, quirky humor, and gift for popularizing serious ideas to “the trolley problem.” Framing the issue as a possible crime that is to be tried in the Court of Public Opinion, Cathcart explores philosophy and ethics, intuition and logic. Along the way he makes connections to the Utilitarianism of Jeremy Bentham, Kant’s limits of reason, St. Thomas Aquinas’s fascinating Principle of Double Effect, and more.

Read with an open mind, this provocative book will challenge your deepest held notions of right and wrong. Would you divert the trolley? Kill one to save five? Would you throw the fat man off the bridge?



A number of smart and generous people reviewed earlier drafts of the book and provided some very creative suggestions. Thanks to my friend Dr. Peter King for his careful analysis of the trolley problem and his provision of several real-world examples. Thanks also to the other members of the King family for their participation in the discussions around the dining room table.

My oldest and dearest friend, Danny Klein, offered loads of encouragement and several great ideas, and his voice was constantly in my head, telling me to make it clearer, slow down, take more steps. As my mentor on a number of books we wrote together, Danny literally taught me how to write a book. Thank you, Danny.

I am fortunate to have two extraordinarily strong women in my life. My wife, Eloise, an excellent writer and editor, read several drafts and improved each of them considerably, but her never-flagging encouragement, support, and love were even more important to me. Thank you, Eloise.

My daughter, Esther, is a much-loved chaplain to many people and dogs, and I am very lucky to be among the beneficiaries of her funny, loving spirit.

Margot Herrera, my editor at Workman, cheerfully ignored my defensiveness and kept urging me to improve the manuscript. Thank you, Margot. Your ideas were excellent.

And a big thank-you to my agent, Julia Lord, who shares an attribute with God: Without her there would be nothing.

The Newspaper Story

Trolley "Heroine" Charged with Manslaughter

D.A. Calls Recipient of City's Valor Award "Outlaw," Cites "Dangerous Precedent"

The Gazette

Tuesday, January 22, 2013

(San Francisco) District Attorney Cleveland Cunningham yesterday announced the grand jury indictment of Daphne Jones of Oakland in the trolley death of Chester "Chet" Farley of San Francisco last October. Ms. Jones was honored by the mayor in December for "showing extraordinary quick-wittedness and valor," when she threw a switch and diverted a runaway trolley onto a siding. The trolley would surely have hit and killed five people if it had continued on the main track, but instead it killed only Mr. Farley, who was standing on the siding. Mr. Cunningham stated that the grand jury had correctly come to the conclusion that Ms. Jones "had no right to play God" when she decided that it was better for Mr. Farley to die than the five others.

Mr. Farley's daughter, Sondra Farley, was present at the news conference and said that she is hopeful that the future conviction of Ms. Jones will help the family "reach closure." The Gazette has learned that the family also has a civil suit pending against both San Francisco Muni and Ms. Jones.

Reached for comment, Sally Jo Kariakidis, one of the five whose lives were spared when Ms. Jones threw the switch, said, "I am so grateful that Ms. Jones was there and was able to think so quickly. I certainly sympathize with Mr. Farley's family, but I don't think that Ms. Jones should be blamed for doing what most of us would have done to minimize the number of casualties from the accident. I hope that doesn't sound heartless, particularly since I am one of the five who survived." Ms. Kariakidis has appeared with Ms. Jones at several public events, most recently a December fund-raiser for the Bay Area Straphangers Association, a trolley safety advocacy organization.

Bay Area residents attending the news conference appeared split in their reaction to the news of Ms. Jones's indictment. A smattering of applause was heard when Mr. Cunningham announced the grand jury's decision. But Floyd Carlucci of Sausalito told reporters that he thought Ms. Jones had made the right choice in pulling the switch. "Do the math," he said.

District Attorney Cunningham said that he realized that the decision of the grand jury "would probably not be popular in all quarters," and he commended them for taking a difficult stand. "It would be a dangerous precedent indeed if we allowed one person to make life-or-death decisions that favor some of our citizens over others," he said.

The Gazette has obtained the original police report of the incident. It can be seen on our website,

The Policeman's Statement

Incident Report

Filed by Patrolman LeRoy Takahashi

San Francisco Police Department

Friday, October 5, 2012

At approximately 4:49 p.m. on October 5, 2012, Patrolwoman Sarah Foster and I received a call from our dispatcher, advising us to proceed to the corner of California Street and Van Ness Avenue, where a trolley had apparently run over a man, causing "grievous injury or death." Patrolwoman Foster and I proceeded to the aforesaid corner, where we observed a city ambulance crew placing the body of a Caucasian male, approximately fifty years of age, into an emergency vehicle. A trolley was parked on the siding, just beyond the site of the alleged accident.

A woman approached us in an agitated state and identified herself as Daphne Jones, 3 Clark Street, Oakland, age twenty-seven. She reported that she had thrown a trolley switch beside the track and diverted the trolley onto the siding where the alleged accident had occurred. We inquired as to why she had acted in this manner, and she indicated that it was in order to save the lives of five other persons who were standing on the main track. We instructed her to remain in our vehicle while we conducted a surveillance of the area and interviewed witnesses.

After speaking with several eyewitnesses, we determined that Ms. Jones's account of the incident was accurate. Upon checking with SFPD HQ, we were informed that no apparent crime had occurred, as Ms. Jones's conduct appeared to meet Exception 3 to Section 192, Manslaughter: "Killing another person when you kill to protect yourself or another from being killed or suffering great bodily injury does not constitute manslaughter, either voluntary or involuntary." We advised Ms. Jones that she might be contacted again by the district attorney's office, but that for now she was free to go. She was still quite agitated, so we drove her to her home and notified our dispatcher at approximately 7:15 p.m.

The Jury Officer's Civics Lesson

Jurors' Welcome

Commissioner of Jurors' Office

Court of Public Opinion

Monday, April 1, 2013

Good morning, prospective jurors. I'm Margaret Sturdevant-Casey, chief jury officer here in the Court of Public Opinion, and it is my pleasure to welcome you here this morning. I hope everyone has found the coffee machine here to my right and the restrooms just beyond the glass doors.

This morning we'll begin jury selection in the case of The People v. Daphne Jones. Twelve of you will be chosen to sit in the jury box and serve as the jurors of record, but, unlike cases in other courts, all of you will serve as associate jurors, because here in the Court of Public Opinion, everyone's opinion matters. This means that, barring serious illness, you must follow the case on television or online and submit your input to the jury when it begins its deliberations. This is, after all, the Court of Public Opinion, and it is only for obvious practical reasons that we must choose twelve to represent all of you in the deliberations. Those of you who aren't seated still have a responsibility to inform yourselves of the facts and arguments in this case and, if possible, form an opinion.

In addition to this requirement of universal participation, the Court of Public Opinion also enjoys a unique status above and beyond that of any other court in the nation. You probably learned in your high school civics course, as I did in mine, that the Supreme Court is the highest court in the land. Well, I'm here to tell you this morning that this is not strictly true. The Court of Public Opinion is actually the highest court in the land. How so? First, while the Supreme Court can strike down a law that is presently on the books by finding that it is incompatible with the U.S. Constitution, the Supreme Court is absolutely unable to create a new law. By contrast, the Court of Public Opinion can and does inspire the creation of new laws nearly every day. That is to say, the laws passed by our representatives in Congress generally reflect a broad public consensus, albeit imperfectly. Second, while the Supreme Court has the sole authority to interpret the Constitution, only the Court of Public Opinion can change the Constitution, as it in fact has done twenty-seven times over the course of the past two hundred twenty–plus years.

If there were no Court of Public Opinion with the authority to change the Constitution, women would not be able to vote today. Laws permitting one person to own another person would in all probability still be in force. And laws governing private behavior in the bedrooms of consenting adults would likely still exist in some states. So I think you can see that your responsibility as jurors on this court—or, if you prefer, citizens in this democracy—is literally awesome.

So, with that, I welcome you to the duty and privilege that come with being a juror in the Court of Public Opinion.

The Prosecutor's Thrust

Summation by District Attorney Cleveland Cunningham

Court of Public Opinion

Friday, April 19, 2013

Ladies and gentlemen of the jury, after three weeks of testimony, you have now heard all the evidence in this matter. It is now time for me to summarize the people's case against the defendant, Daphne Jones.


  • “Jaunty, lucid and concise.”

    —Sarah Bakewell, The New York Times Book Review

    “Thomas Cathcart's charming approach in The Trolley Problem is to dramatize the dilemma by presenting… a trial in the court of public opinion, complete with arguments from lawyers on both sides as well as a psychologist, a professor, a bishop, listeners to a radio call-in show and so forth…”
    The Wall Street Journal

    “The extremely engaging philosopher Thomas Cathcart… explores ethical conundrums in a refreshingly innovative and humorous manner.”
    The New Idealist

On Sale
Sep 10, 2013
Page Count
144 pages

Thomas Cathcart

About the Author

Thomas Cathcart graduated from Harvard with a degree in philosophy, studied theology at the University of Chicago, and embarked on a “checkered career” (his words) from college teaching to hospice management until, at the age of 67, he started his writing life by coauthoring Plato and a Platypus Walk into a Bar with Daniel Klein. Mr. Cathcart and his wife live in New York City.

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