Part of a series of “Today I Learned”s

Two ways of deciding if something is right

There’s a basic disagreement at the heart of moral philosophy:

• Consequentialism says the morality of an action is determined entirely by its outcomes. An action is right if it produces more good than any available alternative, and wrong if it doesn’t.

• The most famous version is Utilitarianism. This attempts to discern right from wrong by optimising some utility function. Outcomes with a higher utility are preferable over outcomes with a lower utility.

  • On this view, lying is not inherently wrong. If lying saves a life and telling the truth ends one, lying is the right thing to do.
  • The challenge is that you rarely know outcomes in advance, and the logic can lead to conclusions that feel deeply wrong - it might justify punishing an innocent person if doing so produces enough benefit for enough people

• Deontological ethics says some actions are right or wrong in themselves, regardless of what they produce. The most systematic version comes from Immanuel Kant, who argued that the moral worth of an action comes from the principle behind it, not its consequences

  • Categorical Imperative test: act only according to a rule you could will to become a universal law. If lying is wrong, it’s wrong because a world where everyone lied whenever convenient would be incoherent - the very concept of communication would collapse
  • On this view, you cannot lie to save a life. The duty not to lie holds absolutely. This is where deontology produces conclusions that also feel uncomfortable.

The trolley problem is a version of this disagreement

The thought experiment exists to make both positions uncomfortable at once. A runaway trolley will kill five people unless you pull a lever to divert it, killing one person instead.

• A consequentialist says pull the lever: five lives outweigh one
• A strict Kantian has more trouble: using one person as a means to save five treats them as a tool rather than an end in themselves, which Kant considered always wrong

Most people’s intuitions about the trolley problem are consequentialist. The same people’s intuitions about other cases - would you harvest one healthy person’s organs to save five dying patients? - can be deontological. This inconsistency is part of what makes ethics unsolved.

A third position worth knowing

Virtue ethics, associated with Aristotle, sidesteps the debate by asking a different question altogether. Instead of “what should I do?”, it asks “what kind of person should I be?” The focus is on character traits rather than rules or calculations. A “virtuous” person develops good judgment through practice and acts well because of who they are, not because they’re following a rule or computing consequences.