Nothing is more certain to my own feelings than this.
There is nothing which I can distinguish in my mind with more clearness than the three states, of indifference, of pleasure, and of pain.

Every one of these I can perceive without any sort of idea of its relation to anything else.

Caius is afflicted with a fit of the colic; this man is actually in pain; stretch Caius upon the rack, he will feel a much greater pain: but does this pain of the rack arise from the removal of any pleasure?
or is the fit of the colic a pleasure or a pain just as we are pleased to consider it?
SECTION III.
THE DIFFERENCE BETWEEN THE REMOVAL OF PAIN AND POSITIVE PLEASURE.
We shall carry this proposition yet a step further.

We shall venture to propose, that pain and pleasure are not only not necessarily dependent for their existence on their mutual diminution or removal, but that, in reality, the diminution or ceasing of pleasure does not operate like positive pain; and that the removal or diminution of pain, in its effect, has very little resemblance to positive pleasure.[10] The former of these propositions will, I believe, be much more readily allowed than the latter; because it is very evident that pleasure, when it has run its career, sets us down very nearly where it found us.

Pleasure of every kind quickly satisfies; and, when it is over, we relapse into indifference, or, rather, we fall into a soft tranquillity which is tinged with the agreeable color of the former sensation.