How Reasoning about Knowledge Helps us understand the World


Rohit Parikh


City University of New York
Brooklyn College and CUNY Graduate Center


Wednesday, 1 January 2020, 14:30 to 15:30


  • A-201 (STCS Seminar Room)


Reasoning about knowledge is an old area but much of the recent technical work goes back to David Lewis and Jaakko Hintikka.  Impetus was given in Computer Science
by the work in 1985 by Halpern and Moses as well as the beautiful work of Chandy and Misra. There is also old work in epistemology in India by Gautma (3rd century) and Gangesa (14th century) who anticipated the more recent work of Gettier on justified true belief.

Much of society works through transmission of knowledge and information. None of us knows all that is relevant, and even if we did, we lack the power to bring about major changes.  Hence working together, preceded by communication is crucial. Communication is basic for  coordination, and coordination is necessary for major actions.  But to  understand communication we need both Logic and Game Theory as well as a bit of the work in psychology.

We will give a bird's eye view of major developments in reasoning about knowledge, concentrating on the work done at the City University of New York by students Krasucki, Plaza, Pacuit, Tasdemir as well as by ourselves, but also giving due attention to friends like R. Ramanajum, Larry Moss, and others like Aumann, Stalnaker and Geanakoplos.

We will also say something about how levels of knowledge influence actions in game theory and how politicians campaigning can find just the right thing to say.