Subsequently, he was invited by Bernard Meltzer to spend a year (1972–1973) in Edinburgh University where he met and worked with many leading AI researchers.

When he went back to Sussex he helped to found what eventually grew into COGS, the School of Cognitive and Computing Sciences.

Much of his energy was devoted to developing new kinds of teaching materials based on POP-11 and Poplog for students learning AI and cognitive science.

In 1991, after 27 years at Sussex, he was offered a research chair in the School of Computer Science at the University of Birmingham, where he started a cognition and affect project (later on the Free Open Source Poplog Portal) and is still on it.

His philosophical ideas were deeply influenced by the writings of Immanuel Kant, Gottlob Frege and Karl Popper, and to a lesser extent by John Austin, Gilbert Ryle, R. M. Hare (who, as his 'personal tutor' at Balliol College discussed meta-ethics with him), Imre Lakatos and Ludwig Wittgenstein.

[7] In 2020 the American Philosophical Association (APA) awarded him the K.Jon Barwise Prize "for significant and sustained contributions to areas relevant to philosophy and computing".