"Suppose there were an experience machine that would give you any experience you desired. Superduper neuropsychologists could stimulate your brain so that you would think and feel you were writing a great novel, or making a friend, or reading an interesting book. All the time you would be floating in a tank, with electrodes attached to your brain. ….Would you plug in? What else can matter to us, other than how our lives feel from the inside?"
Robert Nozick, ‘Anarchy, State and Utopia’