Friedrich Carstanjen, Richard Avenarius and His General Theory of Knowledge… (1906)
“ The best proof of the importance of a theory must be its fruitfulness. But a system so strikingly original as that of Avenarius, and starting from such completely new points of view, contains the promise of great fruitfulness in the mere fact that it directs us into new ways, opens out new perspectives, and shows how it is possible to get quite a new light upon the old problems which are constantly being turned over and over in the same way. ”
