Hermione: "This is Felix Felicis, I suppose? You haven't got another little bottle of -- I don't know--"
Ron: "Essence of Insanity?"
Harry: "Trust me, I know what I'm doing... or at least Felix does."
— Ron and Hermione become suspicious after Harry takes Felix Felicis and says he's going to see Hagrid[src]

Essence of Insanity is a potion which presumably causes irrational behaviour, possibly inflicting the condition of insanity. Ron Weasley wondered if Harry Potter had consumed this instead of Felix Felicis on 21 April, 1997.[1]

Behind the scenes

  • It is unknown if Ron was referring to an actual potion, or was merely speaking metaphorically.


Notes and references

  1. Harry Potter and the Half Blood Prince, Chapter 22 (After the Burial)