Thought Experiments

Philosophy and Ethics

1 The Trolley Problem
— You can pull a lever to divert a runaway trolley, saving five people but killing one. Should you act?
(Explores utilitarianism vs. deontological ethics.)

2 The Experience Machine (Robert Nozick)
— If you could plug into a machine that gives you endless pleasure and perfect happiness but none of it is real, would you do it?
(Questions hedonism and reality.)

3 The Ship of Theseus
— If every plank of a ship is replaced over time, is it still the same ship?
(Explores identity and persistence through change.)

4 The Brain in a Vat
— What if your brain were in a vat, connected to a computer simulating reality — how could you know what’s real?
(Challenges epistemology and realism.)

5 The Chinese Room (John Searle)
— If a person inside a room follows rules to manipulate Chinese symbols perfectly, do they “understand” Chinese?
(Questions whether computation equals consciousness.)

6 Mary’s Room (Frank Jackson)
— Mary knows everything about colour but has never seen it. When she finally sees red, does she learn something new?
(Explores qualia and the limits of physical knowledge.)

7 The Prisoner’s Dilemma
— Two prisoners can betray each other or stay silent. Rational self-interest leads to worse outcomes than cooperation.
(Highlights moral conflict and game theory.)

8 The Veil of Ignorance (John Rawls)
— Imagine designing a fair society without knowing your position in it.
(Examines justice, fairness, and moral reasoning.)

9 The Swampman (Donald Davidson)
— A lightning bolt creates an exact copy of you from a swamp. Is it still you?
(Questions meaning, identity, and consciousness.)

10 The Twin Earth (Hilary Putnam)
— Imagine an identical Earth where water is not H₂O but a similar substance. Does “water” mean the same thing?
(Explores semantics and externalism.)

Physics and Science

11 Schrödinger’s Cat
— A cat in a box is simultaneously alive and dead until observed.
(Illustrates quantum superposition and measurement paradoxes.)

12 Maxwell’s Demon
— A tiny demon sorts molecules to decrease entropy, seemingly violating thermodynamics.
(Challenges the second law of thermodynamics.)

13 Laplace’s Demon
— If an intelligence knew all forces and positions, it could predict the entire future.
(Explores determinism and free will.)

14 The Twin Paradox (Einstein)
— One twin travels near light speed and returns younger than the twin who stayed on Earth.
(Demonstrates time dilation in relativity.)

15 Boltzmann Brain
— Could self-aware minds randomly form from chaos in the universe?
(Raises questions about entropy and the likelihood of reality itself.)

Mind, Reality, and Existence

16 The Simulation Hypothesis (modern)
— What if our universe is a computer simulation indistinguishable from “base” reality?
(Modern extension of the brain-in-a-vat.)

17 Zeno’s Paradoxes
— Achilles can never catch the tortoise because he must first reach halfway, and halfway again.
(Explores motion, infinity, and continuity.)

18 Plato’s Allegory of the Cave
— Prisoners see only shadows on a wall and mistake them for reality.
(Addresses perception, truth, and enlightenment.)

19 The Butterfly Dream (Zhuangzi)
— A man dreams he’s a butterfly. Upon waking, he wonders if he’s a man who dreamed he was a butterfly — or a butterfly dreaming he’s a man.
(Examines self and reality.)

20 The Infinite Library (Borges’ Library of Babel)
— Imagine a library containing every possible combination of letters and words.
(Reflects on meaning, order, and chaos.)

21 The Teleporter Problem