Genius and Madness

Genius and madness… Is there really much in common between them? Is genius simply one of the many forms of insanity? The greatest criminal psychiatrist of the 19th century, Cesare Lombroso, who was consistently declared a genius, a madman, and then a genius again, presents in his most famous work a striking theory that genius is simply incompatible with normality—specifically, normality not in a mundane sense, but in a purely clinical sense of the word. So, what, according to Lombroso, constitutes the "madness of geniuses"?