War
War- a series of battles waged between two foes, resulting in destruction and a great loss of life.
However, a torrent of flame, upon flooding a forest, leaves more than mere ash and silence. The ash will nourish a new generation of plants, which will thrive once more in the serenity of silence.
Thus, war can also be a productive force, as has spawned many great thinkers, creators, and technologies.
Diarrhoea
"Diarhhoea, - disorder consisting in the too frequent evacuation of too fluid fæces, sometimes attended with griping pains"
"Often this gripping pain is followed by thrilling, bowel-wrenching influx of sheer pleasure and consummate relief, especially after a desperate dash for the nearest lav." - This is a psychoemotional invertion.
"Diarhhoea, - a plight for the healthy but a boon for the chronically constipated." - and this is a clinical one.