A Philosophy of The Possible

Few reference works in philosophy have articles on hope. Few also are systematic or large-scale philosophical studies of hope. Hope is admitted to be important in people's lives, but as a topic for study, hope has largely been left to psychologists and theologians.

The cogito ergo sum of Descartes is one of the best-known (and simplest) of all philosophical formulations, but ever since it was first propounded it has defied any formal accounting of its validity. How is it that so simple and important an argument has caused such difficulty and such philosophical controversy?