“The question 'what shall we do about it' is only asked by those who do not understand the problem. If a problem can be solved at all, to understand it and to know what to do about it are the same thing. On the other hand, doing something about a problem which you do not understand is like trying to clear away darkness by thrusting it aside with your hands. When light is brought, the darkness vanishes at once. This applies particularly to the problem.”