"[...]eternally existing and disappearing. But this philosophy, correct as it is as regards phenomena in general, viewed as a picture, is insufficient to explain the individual phenomena of which the picture of the universe is composed, and as long as we cannot do that we are not clear about the general picture. In order to study these individual phenomena we are obliged to take them out of their natural or social connection, and examine each of them by itself according to its own form and its particular origin and development. This is the task of natural science and[...]".