Suppose someone — who, for reasons that will become apparent, Quinn calls the self-torturer — has a special electric device attached to him. The device has 1001 settings: 0, 1, 2, 3, …, 1000 and works as follows: moving up a setting raises, by a tiny increment, the amount of electric current applied to the self-torturer's body. The increments in current are so small that the self-torturer cannot tell the difference between adjacent settings. He can, however, tell the difference between settings that are far apart. And, in fact, there are settings at which the self-torturer would experience excruciating pain. Once a week, the self-torturer can compare all the different settings. He must then go back to the setting he was at and decide if he wants to move up a setting. If he does so, he gets $10,000, but he can never permanently return to a lower setting. Like most of us, the self-torturer would like to increase his fortune but also cares about feeling well. Since the self-torturer cannot feel any difference in comfort between adjacent settings but gets $10,000 at each advance, he prefers, for any two consecutive settings s and s+1, stopping at s+1 to stopping at s. But, since he does not want to live in excruciating pain, even for a great fortune, he also prefers stopping at a low setting, such as 0, over stopping at a high setting, such as 1000
This passage as stated states that the increments to be increased are of the devices settings (i.e. amount of electric current). But the "puzzle" seem to arise when we consider increments of degrees of pain.