CALEF, or CALFE, Robert, author, died about 1723. He was a Boston merchant, and powerfully attacked the witchcraft delusion in a book called "More Wonders of the Invisible World" (London, 1700 ; Salem, Massachusetts, 1796). The title was suggested by Cotton Mather's " Wonders of the Invisible World." Calef's plain facts and common-sense arguments had a powerful effect on public opinion, and contributed much to the decline of the delusion. His book irritated Mather, who called Calef "a weaver turned minister" and "a coal from hell," and finally prosecuted him for slander. Dr. Increase Mather, president of Harvard College, ordered the wicked book to be burned in the College-yard. The members of the Old North church published a defense of their pastors, the Mathers, entitled "Remarks upon a Scandalous Book," etc., with the motto, "Truth will come off Conqueror." Calef's book made him unpopular, and Samuel Mather, in his life of his father, says : "There was a certain disbeliever of witchcraft who wrote against this book; but, as the man is dead, his book died long before him."