weltschmerz [ˈvɛltˌʃmɛrts] n.
1.) A weary or pessimistic feeling about life; an apathetic or vaguely yearning attitude (O.E.D. 2nd Ed.).
Etymology: German : Welt, world + Schmerz, pain (from Middle High German smërze, from Old High German smerzo)
"Too much questioning and too little active responsibility lead, almost as often as too much sensualism does, to the edge of the slope, at the bottom of which lie pessimism and the nightmare or suicidal view of life. But to the diseases which reflection breeds, still further reflection can oppose effective remedies; and it is of the melancholy and Weltschmerz bred of reflection that I now proceed to speak" ("Is Life Worth Living?", William James, 1895).
My housemates are away and I'm taking care of their cats. So, I'm reading in my garden yesterday afternoon when one of the cats comes over the fence carrying a pigeon bigger than he is. It's not dead, though, and the cat is just torturing it. What is the correct response in this situation? Am I obligated to put the pigeon out of its misery? Why? The cat is the one being immoral, not me. By this logic, aren't we obligated to stop all cats (even lions, tigers, etc.) from torturing their prey?