Common Belief and Common Knowledge

Georg Meggle

[Back to paper list] [Start page] [Alphabetical index]

Keywords: Common Belief, Common Knowledge, Mutual Belief, Mutual Knowledge, Subjective Facts, Intersubjective Facts.

: Though concepts of Common Belief and Common Knowledge are of utmost importance for all (investigations of) interpersonal relations, they are nearly nowhere defined explicitly. Here they are. But, as a first step, only within the socalled additive approach, i.e., by taking some concepts of (for sake of simplicity: strong and strictly lrational) single-person-relative beliefs as their basis. The resulting concepts of Common Belief and Common Knowledge are (proved to be) regulated by nearly the same logical principles as are the individualistc Belief- and Knowledge-concepts. This makes working with these concepts quite easy. Finally, the weaker concepts of Mutual Belief and Knowledge will be defined and compared with Common Belief and Knowledge.

here to obtain the paper in PDF format.

Georg Meggle

Spinning Ideas, Electronic Essays
Dedicated to Peter Gärdenfors on His Fiftieth Birthday