The cases of tarantism and jettatura – an 18th-century revival of the Ficinian and Baconian theory of fascinatio oculis – are examples of that magical magnetism, which affects both nature and man, and is characterised by an apparent action at a distance. The actio in distans is perceived as weird and mysterious because, while the phenomena are evident to the senses, their causes are unknown and resist the laws of nature. In my talk, I will analyse the contribution of Neapolitan naturalists, such as Ferrante Imperato, to the history of tarantism, and of Neapolitan jurists, such as Nicola Valletta, to the theories of oculus malus, through the latest peculiar and successful revisitation of a noble and ancient philosophical tradition.