Home & News Activities Joining the Society Archives OUDCE weekend
philosophy courses
The Review Members' Weekend Away Weekend
(formerly Intl. Event)
Friday Group Regional Groups Discussion Forum Chadwick Prize Talbot Prize Contacts Links & Portraits

Members' Weekend, 03 - 04 September 2016

Thought Experiments

Links in the below time-table activate MP3 audio recordings of the corresponding talks. Talk recordings and supporting material are also linked from talk summaries further below.

Saturday 03 September

1.30 pm Registration
1.45 pm Peter Gibson: Introduction: Problems with Thought Experiments
2.00 pm Ryan Meade: Thought Experiments
2.45 pm Janet Cox: The Beetle in the Box
3.30 pm Tea/Coffee
4.00 pm Mike Donnan: Grue
4.45 pm Marianne Talbot: Twin Earth
5.30 pm Panel discussion
6.30 pm Bar
7.00 pm Annual Dinner and presentation of Chadwick & Boethius prizes
9.00 pm General discussion to be continued in the bar
Bar open till 10:30 pm

Sunday 04 September

8.00 am Breakfast (RH residents only)
9.30 am Peggy Verrall: The Ship of Theseus
10.15 am Bob Stone: The Trolley Problem
11.00 am Tea/Coffee
11.30 am Panel Discussion
12.30 Bar, then Lunch
2.00 pm Course disperses

The Talks in chronological order.

Peter Gibson: Introduction: Problems with Thought Experiments
Audio recording (MP3 format)
Talk text (PDF format)

Ryan Meade: Thought Experiments
Philosophers may have perfected the thought experiment but it is a tool used across disciplines. For example, a thought experiment precedes every scientific experiment, and every law drafted. Memorable thought experiments involve fanciful facts, but more mundane thought experiments are in daily use in critical reasoning and conjecture. Along with the contribution of philosophy, this paper will sketch the history of thought experiments and explore their utility across disciplines. The lecturer will draw on his use of thought experiments in teaching law, ethics, and legal theory.
Audio recording (MP3 format)

Janet Cox: The Beetle in the Box
In the Philosophical Investigations (§293), Wittgenstein asks us to consider a situation where everyone has a box containing something (or perhaps nothing) which we call a "beetle". Each of us can see inside only our own private box – no one else's. We all talk to each other about "beetles". How do we make sense of "beetle" How does this use of "beetle" work? Although this thought experiment has prompted many analyses, the talk will concentrate on Saul Kripke's account in Wittgenstein on Rules and Private Language.
Audio recording (MP3 format)
Slides (PDF format)

Mike Donnan: Grue
Suppose that every emerald that has ever been observed up until midnight, 31st December 2016, has been green. You predict that the first emerald to be observed in 2017 will be green too, whereas your chum - who speaks a dialect which avoids 'green' but employs the unfamiliar predicate 'grue' – predicts (after we have translated his dialect utterance) that the emerald will be blue. Yet you both have the same evidence and employ analogous reasoning. That looks to be a riddle worth discussing.
Audio recording (MP3 format)
Slides (PDF format)
Handout (JPEG format)

Marianne Talbot: Twin Eart

I shall be talking about the Twin Earth thought experiment which purports to show, as Hilary Putnam put it, that 'thoughts ain't in the head' (Putnam 1975). I shall look at the objection that the thought experiment is not 'scientifically respectable' because it is simply not possible for something that looks, tastes and (in particular) behaves like water to be anything other than H20.
Audio recording (MP3 format)
Slides (PDF format)

Peggy Verrall: The Ship of Theseus
The Ship of Theseus thought experiment (or Trigger's Broom) concerns an old ship which is preserved by the gradual replacement of its deteriorating planks. If parts of the ship are gradually replaced, at what point does the original cease to be itself? What relevance, if any, does this have with reference to who we are?
Audio recording (MP3 format)
Slides (PDF format)

Bob Stone: The Trolley Problem
After outlining a few of the best-known examples – e.g. the one where you can save three people tied to the line only by pushing a fat man off a bridge into the trolley's path – I'll discuss a) the purpose and 'results' of the thought experiments, b) the conflict between what seems the rational course of action and the strong intuition that it is wrong, c) the degree to which intuition is a guide to what is right, d) a rule-utilitarian approach, and e) fundamental drawbacks with the problems as thought experiments.
Audio recording (MP3 format)
Talk text (PDF format)
Handout (PDF format)
Slides (PDF format)

The Speakers

  1. Ryan Meade is the Director of Regulatory Compliance Studies at Loyola University Chicago, teaching law courses related to health policy and clinical research. His interests include philosophy of law, history of Anglo-American law, and medieval legal theory (particularly Aquinas and Suarez). He received a B.A. from Northwestern University, a J.D. from Cornell University, and is an LLM candidate at the University of Edinburgh.
  2. Janet Cox has taken philosophy courses with the OU, a Diploma with Warwick University and, most recently, courses with OUDCE. Inspired by last year's Necessity and Possibility weekend, Janet joined the OUDCE Philosophy Society to have more interaction with other philosophy lovers. She hopes to study the later Wittgenstein in more depth.
  3. Mike Donnan Having graduated in chemistry, despite a certain maladroitness in the laboratory, Michael stumbled into the world of intellectual property and eventually qualified as a patent attorney. In his 40s and purely out of curiosity, he enrolled on an introductory course in philosophy at Birkbeck College, became captivated, and after some procrastination studied there for a BA, and then an MA.
  4. Marianne Talbot has been Director of Studies in Philosophy at OUDCE since 2001. In 2017 she will have lectured for the colleges of the University of Oxford for 30 years. She is delighted to find herself President of the Philosophical Society, probably the largest (and certainly the best!) amateur philosophy society in the UK.
  5. Peggy Verrall studied some philosophy as part of reading modern history at St Anne's (1959). She has reignited her interest since retirement from teaching full time in 1996.
  6. Bob Stone is a retired classics teacher, who specialised at university in ancient Greek philosophy and got interested in the new-fangled stuff too. Since retiring, he's resumed that interest with a vengeance. His philosophy in a nutshell: "For every complex problem there is an answer that is clear, simple, and wrong" (H.L. Mencken).


  • Tamar Gendler (2000) Thought Experiment: On the Powers and Limits of Imaginary Cases.
  • Martin Cohen (2005) Wittgenstein's Beetle and Other Classic Thought Experiments
  • Goodman, Nelson, Fact, Fiction, and Forecast, 4th ed., Harvard (1983), esp Ch III, is the primary source. For a useful introduction see Bortolotti, Lisa, An Introduction to the Philosophy of Science, Polity Press (2008), pp. 68-71.

General reading