Emily Brontë’s novel focuses upon the destructive relationship between Heathcliff and Cathy. While the ‘madness’ elements in this novel are never made fully explicit, Heathcliff and Cathy’s obsession with each other is perceived as mentally damaging to both themselves and many of the other characters. Heathcliff’s sanity is the most frequently commented upon in the text to the extent that in the light of his behaviour and cruelty his humanity is questioned, ‘Is Heathcliff a man? If so is he mad? And if not is he a devil?’ Despite this, it is Cathy who is diagnosed in the text with a ‘brain fever’ of indeterminable origin, although there are strong implications that this has been a ‘self-driven’ illness of sorts.

'Be with me always- take any form- drive me mad! only do not leave me in this abyss where I cannot find you! Oh God! it is unutterable! I cannot live without my life! I cannot live without my soul!' p.167

'I have no pity! I have no pity! the more the worms writhe, the more I yearn to crush out their entrails! It is a moral teething, and I grind with greater energy, in proportion to the increase of pain.' p. 150

'Is Heathcliff a man? If so, is he mad? And if not, is he a devil?' p.134