ABSTRACT
Around 1903, the German physician, psychologist, scientist, philosopher and general polymath Hermann von Helmholtz described his work in surprisingly unguarded tone:
“I was like a mountaineer who, not knowing the path, must climb slowly and laboriously, is forced to turn back frequently because his way is blocked but discovers, sometimes by deliberation and more often by accident, new passages which lead him onward for a distance.” (Helmholtz, 1954)
