Summarize this paragraph in only one sentence with your own words. Nozick’s experience machine aimed to disprove the essential claim of utilitarianism, "that happiness is desirable, and the only thing desirable, as an end". In 1826, the philosopher who wrote those words, John Stuart Mill, became mired in unhappiness. In his autobiography, Mill describes what we now recognise as depressive anhedonia: "I was in a dull state of nerves, such as everybody is occasionally liable to; unsusceptible to enjoyment or pleasurable excitement; one of those moods when what is pleasure at other times, becomes insipid or indifferent."