Malleus Maleficarum (1486)
translated by Montague Summers 
This is the best known (i.e., the most infamous) of the witch-hunt manuals. Written in Latin, the Malleus was first submitted to the University of Cologne on May 9th, 1487. The title is translated as "The Hammer of Witches". Written by James Sprenger and Henry Kramer (of which little is known), the Malleus remained in use for three hundred years. It had tremendous influence in the witch trials in England and on the continent. This translation is in the public domain.
The Malleus was used as a judicial case-book for the detection and persecution of witches, specifying rules of evidence and the canonical procedures by which suspected witches were tortured and put to death. Thousands of people (primarily women) were judically murdered as a result of the procedures described in this book, for no reason than a strange birthmark, living alone, mental illness, cultivation of medicinal herbs, or simply because they were falsely accused (often for financial gain by the accuser). The Malleus serves as a horrible warning about what happens when intolerence takes over a society.
Although the Malleus is manifestly a document which displays the cruelty, barbarism, and ignorance of the Inquisition, it has also been interpreted as evidence of a wide-spread subterranean pagan tradition which worshiped a pre-Christian horned deity, particularly by Margaret Murray.
The source version of this text, with notes and additional material, can be found at MalleusMaleficarum.org [External Site].