Although sometimes loosely used as synonyms, it is necessary to note
that there is a well-defined distinction between Weltschmerz and
pessimism. Weltschmerz may be defined as the poetic expression of an
abnormal sensitiveness of the feelings to the moral and physical evils
and misery of existence--a condition which may or may not be based upon
a reasoned conviction that the sum of human misery is greater than the
sum of human happiness. It is usually characterized also by a certain
lack of will-energy, a sort of sentimental yielding to these painful
emotions. It is therefore entirely a matter of "Gemüt." Pessimism, on
the other hand, purports to be a theory of existence, the result of
deliberate philosophic argument and investigation, by which its votaries
have reached the dispassionate conclusion that there is no real good or
pleasure in the world that is not clearly outweighed by evil or pain,
and that therefore self-destruction, or at least final annihilation is
the consummation devoutly to be wished.

James Sully, in his elaborate treatise on Pessimism,[1] divides it,
however, into reasoned and unreasoned Pessimism, including Weltschmerz
under the latter head. This is entirely compatible with the definition
of Weltschmerz which has been attempted above. But it is interesting to
note the attitude of the pessimistic school of philosophy toward this
unreasoned pessimism. It emphatically disclaims any interest in or
connection with it, and describes all those who are afflicted with the
malady as execrable fellows--to quote Hartmann--: "Klageweiber
männlichen und weiblichen Geschlechts, welche am meisten zur
Discreditierung des Pessimismus beigetragen haben, die sich in ewigem
Lamento ergehen, und entweder unaufhörlich in Thränen schwimmen, oder
bitter wie Wermut und Essig, sich selbst und andern das Dasein noch mehr
vergällen; eine jämmerliche Situation des Stimmungspessimismus, der sie