Professor Peter Adamson: Avicennan and Cartesian Doubt

It’s 100 years since the first Royal Institute of Philosophy Lectures were held in 1925. To mark the centenary, the 2025/6 London Lecture Series focuses on the theme Philosophy in Retrospect and in Prospect. Distinguished philosophers have been invited to reflect on where their area of the discipline has got to over the last hundred years, and/or where it might go – or should go – over the next hundred.

All lectures include a post-lecture "in conversation" session with our Academic Director Edward Harcourt, followed by audience Q&A.

It has often been noticed that Ibn Sīnā (Avicenna, d. 1037) and René Descartes (d. 1650) offered similar arguments for the immateriality of the self or soul. In Ibn Sīnā, we have the “flying man argument,” which infers this conclusion from the possibility of grasping one’s own existence without access to the senses; in Descartes we have the dualist implications drawn from the cogito. Not only are the arguments similar, but also objections that have been posed to them: both are thought to suffer from the “masked man” fallacy, because they make an inference similar to thinking that Peter Parker is not Spiderman, because one can be aware of Peter Parker without being aware of Spiderman. But in this talk, Professor Peter Adamson will argue that “arguments from doubt” may actually be stronger than they seem. Scholarship on Descartes has already offered useful tools for understanding how Ibn Sīnā wanted the flying man to work, along with other doubt-based arguments in the Avicennan corpus and in later thinkers who respond to him in the Islamic world.

Peter Adamson is Professor of Late Ancient and Arabic Philosophy at the LMU in Munich. He is the author of Al-Kindī and Al-Razī in the series Great Medieval Thinkers from Oxford University Press, and has edited or co-edited numerous books, including The Cambridge Companion to Arabic Philosophy and Interpreting Avicenna: Critical Essays. He is also the host of the History of Philosophy podcast (www.historyofphilosophy.net), which appears as a series of books with Oxford University Press.