Notes to Shakespeare, Volume III: The Tragedies

Dr. Johnson's reaction to Shakespeare's tragedies is a curious one, compounded as it is of deep emotional involvement in a few scenes in some plays and a strange dispassionateness toward most of the others. The reality of witchcraft or enchantment, which, though not strictly the same, are confounded in this play, has in all ages and countries been credited by the common people, and in most, by the learned themselves. These phantoms have indeed appeared more frequently, in proportion as the darkness of ignorance has been more gross; but it cannot be shown, that the brightest gleams of knowledge have at any time been sufficient to drive them out of the world. The time in which this kind of credulity was at its height, seems to have been that of the holy war, in which the Christians imputed all their defeats to enchantments or diabolical opposition, as they ascribed their success to the assistance of their military saints.