In everyday speech, the word “professional” has an
ambiguous ring, applied to one who follows, by way of
profession, what is ordinarily regarded as a pastime (e.g.,
a sport), or disparagingly applied to one who “makes a
trade” of politics and the like. In this sense it is contrasted
with “amateur”, one who does something, literally, for the
love of it, without remuneration. The latter is generally
regarded as superior to the former; remuneration being
considered as likely to irremeably invest the activity with
self-interest, resulting in the task at hand being merely
accomplished with the minimally sufficient expertise and
skill to obtain the offered remuneration, whereas the
amateur strives to do whatever task is at hand as well as
he or she possibly can, “ excellence for its own sake”