why are thought experiments useful?
- clarification: help throw light on difficult/abstract ideas
- testing: provide reasons for/against a hypothesis
- because can’t consult actual experiments
why not use actual experiments?
- physically, technologically, financially impossible or currently unfeasible to conduct
- ethically impermissable
destructive thought experiments
- providing reasons to reject a hypothesis
- e.g. by showing that it is internally/externally inconsistent
constructive thought experiments
- providing reasons to accept a hypothesis
- e.g. by illustrating its claims and therefore providing understanding
Brown on thought experiments (a priori view, intuition view)
thought experiments help us acquire worldly truths a priori and therefore transcend empirical knowledge
objection to a priori view
intuitions need not be shared as various experiments have shown and can lead us astray
Norton on thought experiments (a posteriori view, argument view)
thought experiment is an (implicit or explicit) argument with premises grounded in experience
objection to a posteriori view
- presented as arguments may lose force
- how can we claim the conc. of such arguments provide new empirical data?
how to counter a thought experiment?
- question the plausibility of initial conditions
- cast doubt on justifiability of conclusion
- put forth thought experiments with contradictory conclusions
- criticise details as inadequate
- adopt a more general sceptical attitude towards them
Maxwell’s demon
though experiment showing that contrary to classical second law of thermodynamics, entropy can sometimes decrease
Searle’s Chinese room
- thought experiment showing that the mere manipulation of symbols, even if successful at language tasks, does not entail understanding
- challenges Turing test
Thomson’s violinist
thought experiment which challenged anti-abortion argument that violating rights is morally wrong but there are situations in which unplugging not morally wrong
Jackson’s Mary and the black-and-white room
- seeks to disprove physicalism (only physical things exist and facts about them can be fully captured by physics
- Mary born in black-and-white room, knows every fact but will still learn something new if sees color
