As Julian Baggini points out in his short and lucid book devoted to an
important but neglected subject, the philosophy of complaint, the
propensity to complain represents a distinguishing feature of our
species. Only Homo sapiens can conceive of a world different from the
one in which he currently finds himself. The inevitable gulf between
things as they are and as they ought to be is what gives rise to
complaint. Link:
http://books.guardian.co.uk/reviews/recommended/politicsphilosophyandsociety/0,,2286938,00.html###