of the truth, the master-builder of human happiness.

  No one rejects, dislikes, or avoids pleasure itself, because it is pleasure,

  but because those who do not know how to pursue pleasure rationally encounter

  consequences that are extremely painful. Nor again is there anyone who loves

  or pursues or desires to obtain pain of itself, because it is pain, but because

  occasionally circumstances occur in which toil and pain can procure him some

  great pleasure. To take a trivial example, which of us ever undertakes laborious

  physical exercise, except to obtain some advantage from it? But who has any