Thinking about the Impossible

Course summary

Thinking about the Impossible


Mathematicians tried to square the circle for centuries before realising that it can’t be done. Time travel stories abound, even though time travel may well turn out to be impossible. In daily life we often think about impossible things. If Jane makes an error in multiplication, for example, and comes to believe 56 times 12 is 762 she is entertaining an impossible thought. How can we understand the content of thoughts about impossible things? Philosophers have suggested that thought content can be captured in terms of possible worlds. But if a thought is impossible it is not true in any possible world. Moreover, if we admit the existence of possible worlds, we have to address the question of what a possible world is, and what it is like. Come and help us tussle with these issues. There will be plenty of opportunity to discuss these fascinating questions with the speakers and with other participants.

Programme details


2.45pm Course Registration

3.00pm Belief, truth, and meaning

4.30pm Tea / coffee

5.00pm Impossible thinking

6.30pm Break / bar open

7.00pm Dinner

8.15pm- Meaning beyond the limits of logic
9.30pm MARK JAGO


8.15am Breakfast (residents only)

9.30am Impossible worlds

10.45am Coffee / tea

11.15am Q & A
Questions directed by MARIANNE TALBOT

12.30pm Break / bar open

1.00pm Lunch

2.00pm Course disperses

Recommended reading

Berto, F., “Impossible Worlds.” In The Stanford Encyclopedia of Philosophy. Edited by Edward N. Zalta. 2009. Revised 2013.
Priest, G., ed., Special Issue: Impossible Worlds. Notre Dame Journal of Formal Logic 38.4 (Fall 1997a).
Jago, M., The Impossible: An Essay on Hyperintensionality. Oxford: Oxford University Press, 2014
Jago, M., “Impossible Worlds”, Noûs 49, 713–728, 2015
Lewis, D., On the Plurality of Worlds, Oxford, 1986.
Nolan, D. P., “Impossible Worlds.” Philosophy Compass 8.4 (2013): 360-372
Stalnaker, R., “Impossibilities.” Philosophical Topics 24 (1996): 193–204. Reprinted in Stalnaker’s Ways a World Might Be (Oxford: Clarendon, 2003).
Stalnaker, R., “On Logics of Knowledge and Belief”, Philosophical Studies 128, 169-199, 2006.
Yagisawa, T., Beyond possible worlds, Philosophical Studies 53, 175-204, 1988

USEFUL WEBSITES (An overview of key issues with bibliographies) (a website containing impossible imagery) Mark Jago’s papers


Accommodation for this weekend is at Rewley House for Saturday night only.
Depending on availability it may also be possible to extend your stay, please enquire at the time of booking for availability and prices.
All bedrooms are modern, comfortably furnished and each room has tea and coffee making facilities, Freeview television, and Free WiFi and private bath or shower rooms.
Unfortunately it is not yet possible to book twin room accommodation online, so if you wish to book a twin room, please send in your completed enrolment form or contact the Day & Weekend Events Office, Email:; Telephone: + 44 (0) 1865 270380 / 270368.


includes coffee/tea: £76.50
Single B&B Saturday: £72.60
Single Room Only Saturday: £62.00
Twin B&B Saturday (per person): £52.10


If you are in receipt of a state benefit you may be eligible for a reduction of 50% of tuition fees.

If you do not qualify for the concessionary fee but are experiencing financial hardship, you may still be eligible for financial assistance.

Concessionary fees for short courses


Ms Marianne Talbot

Director of Studies

Marianne Talbot B.A., B.Phil., has been Director of Studies in Philosophy at Oxford University’s Department for Continuing Education since 2001. She has written several of Oxford’s popular short online courses on Philosophy, and her podcasts (notably on critical reasoning) have been downloaded over 5 million times. Marianne specialises in logic, ethics and the philosophy of mind. The topic of knowledge is her particular current interest.  


Dr Mark Jago


Mark Jago, is Associate Professor in Philosophy at the University of Nottingham. Previously he was at Macquarie University in Sydney, Australia, having studied logic and computer science at Nottingham. His PhD is on logic in Artificial Intelligence. Nowadays, he mainly writes on metaphysics, logic, epistemology, and philosophy of language. He is currently writing on what truth is; how we think about impossible things; what material objects are; how to think about essence; and what propositions are. He is also interested in philosophical curiosities such as holes, absences, and negative facts.

Dr Ira Kiourti


Ira Kiourti, holds a PhD from the University of St Andrews, as well as Masters degrees from St. Andrews and the University of Glasgow, where she converted into Philosophy having originally studied Fine Art. Her doctoral thesis, which explores extreme realism about impossible worlds, was completed under the supervision of Katherine Hawley and Graham Priest and as part of the Arché Research Centre. She has since been a Visiting Fellow at the Institute of Philosophy and a Guest Teacher at the London School of Economics. She works on contemporary metaphysics, especially modality and time, and is currently an independent researcher living between Greece and the UK.