Possibilans are those that celebrate the vastness of our ignorance, are unwilling to commit to any particular made-up story, and take pleasure in entertaining multiple hypotheses.

The term "Possibilian" was popularized by David Eagleman after his friend Robbie Parrish came up with the term while sitting on a balcony looking out over the ocean.

The manifesto of the Possibilian movement is SUM, the bestselling work of fiction by David Eagleman.

Eagleman is finishing his next book, Why I am a Possibilian for publication in 2010.