Three Friends Against the Plan
Foucault's PendulumThe shifting relationship among Casaubon, Belbo, and Diotallevi lets each man contribute to the Plan while responding differently to its dangers.
increasing
Bearing strength in each event
decreasing
A Shared Game

Three Different Motives
Belbo's play
Belbo uses the computer to test language and escape his fear of writing. Casaubon brings historical material, while Diotallevi supplies cabalistic knowledge.
A common project
Their distinct interests make the collaboration productive. They imagine that humor and distance will protect them from taking its conclusions seriously.
Unequal Involvement

Diverging Attachments
Casaubon's confidence
Casaubon believes he can remain an ironic observer, particularly because Lia offers a life outside the game. Belbo increasingly treats the fiction as a possible answer to his disappointments.
Diotallevi's devotion
Diotallevi reads the project through sacred language. The same activity that amuses one participant becomes spiritual practice for another.
The Last Counsel

A Shared Guilt
Diotallevi's warning
Diotallevi tells Belbo that their manipulation of texts may have crossed a line. Belbo faces the warning but is already entangled in his own desire to believe.
A final separation
Casaubon leaves for Paris, Belbo is trapped there, and Diotallevi dies. The collaboration that created the Plan cannot reunite to correct it.
During their early work together
As the Plan expands
Shortly before Belbo leaves for Paris