The book of knowledge treating of the wisdom of the ancients

Attributed to Erra Pater, this work belongs to the tradition of practical compendia that gather prognostication, medicine, and natural lore under the banner of ancient wisdom. Its historical importance lies in the long life of such popular occult handbooks; readers will encounter a mixture of calendrical guidance, astrology, and old-fashioned advice on signs, seasons, and remedies.

Erra Pater is a pseudonymous or partly legendary name attached to popular prognostication and astrological calendars, especially texts of practical astrology and almanac literature. The name became associated with vernacular occult instruction rather than with a securely identified historical author.