Leonardo Vairo (1543/44–1603) was Bishop of Naples and wrote a detailed treatise on the evil eye, stimulated in all likelihood by the particular prevalence there of belief in its reality and dire effects. He is thorough in his examination of how the phenomenon is supposed to work, its long history, its motives, the kinds of people who inflict harm by means of it, and how to counter its effects successfully. He illustrates his work with many anecdotal instances, several drawn from personal experience, and calls on the sciences as well as religion for his arguments and observations.