The Malleus maleficarum [of Heinrich Kramer and James Sprenger.] Translated with introductions, bibliography, and notes by Montague Summers

For nearly three centuries Malleus Maleficarum (the witches hammer) was the professional manual for witch hunters. This book by two of the most famous Inquisitors of the age is still a document of the force of that eras beliefs. Under a Bull of Pope Innocent VIII, Kramer and Sprenger exposed the heresy of those who did not believe in witches and set forth the proper order of the world with devils, witches, and the will of god. Even if you do not believe in the witchcraft, the world of 1484 did.