Verbal Irony (Chapter 17/ Pages 230-240)

" 'In fact,' said Mustapha Mond, 'you're claiming the right to be unhappy.'
  'All right then,' said the Savage defiantly, 'I'm claiming the right to be unhappy.'
  'Not to mention the right to grow old and ugly and impotent; the right to have syphilis and cancer; the right to have too little to eat; the right to be lousy; the right to live in constant apprehension of what may happen tomorrow; the right to catch typhoid; the right to be tortured by unspeakable pains of every kind.' There was a long silence.
  'I claim them all,' said the Savage at last."

~ Brave New World, page 240

This whole portion of the discussion between Mustapha and John is verbally ironic. This verbal irony is that John is saying he wants to be unhappy, but he really means that he knows he must accept this unhappiness to experience true joy. The other citizens of the Society would look at these things and be repulsed. But they live with false happiness. Those people can't understand that there must be pain with joy. When John says he claims all the horrible things, he literally is claiming them, but more importantly, he is also taking all the good things that counter them. This irony reveals one of the themes of the book. We can go through life pretending to be happy when we are actually numb and simply avoiding our problems, or we can suffer through those pains, solve our issues, and also experience the real pleasures in life.