This is a new English translation of a classic of medieval Islamic learning, which illuminates the intellectual debates of its age and speaks vividly to the concerns of our own. It is the most famous work of the Brethren of Purity, a tenth-century esoteric fraternity based in Basra and Baghdad. In this rich allegorical fable, the exploited and oppressed animals pursue a case against humanity. They are granted the gift of speech and presented as subjects with views and interests of their own.