The trolley problem is a thought experiment in ethics and moral philosophy, first introduced by the philosopher Philippa Foot in 1967, but it was later developed into its most popular form by Judith Jarvis Thomson. The basic setup of the problem is as follows: There is a runaway trolley moving down the railway tracks. Ahead, on the tracks, there are five people tied up and unable to move. The trolley is headed straight for them. You are standing some distance off in the train yard, next to a lever. If you pull this lever, the trolley will switch to a different set of tracks. Unfortunately, there is one person on the side track. You have two options: Do nothing, and the trolley kills the five people on the main track. Pull the lever, diverting the trolley onto the side track where it will kill one person.
The question is: what is the most ethical choice? This hypothetical situation presents a moral dilemma that brings into focus two principal ethical frameworks: consequentialism (or utilitarianism specifically) and deontological ethics. Utilitarianism would suggest that you should pull the lever, as this course of action would result in fewer deaths. This ethical framework holds that the best action is the one that maximizes overall happiness or ‘utility’. In this case, the death of one person is a terrible thing, but it is ‘better’ than the death of five people.
On the other hand, deontological ethics, which is primarily associated with Immanuel Kant, argues that certain actions are inherently right or wrong, regardless of their consequences. From this perspective, actively pulling the lever to cause someone’s death (even to save five others) could be seen as morally wrong because it involves deliberately harming an individual. A deontologist might argue that one should not interfere and let the trolley continue on its course, as actively causing harm is morally reprehensible, even if it leads to a better overall outcome.
The trolley problem sparks intense debates in philosophy and ethics because it underscores the tension between these two approaches. It forces us to confront the question of whether the ends justify the means and challenges us to think critically about the principles that underlie our moral decisions. In recent years, the trolley problem has found real-world applications in discussions about autonomous vehicles. If an accident is unavoidable, how should a self-driving car be programmed to react? Should it prioritize the lives of its passengers or pedestrians? The discussion of these questions brings the trolley problem out of the realm of pure philosophy and into practical, and life-critical, decision-making.