You can either read something many times in order to be assured that you got it all, or else you can define your purpose and use techniques which will assure that you have met it and gotten what you need.

Few can contemplate without a sense of exhilaration the splendid achievements of practical energy and technical skill, which, from the latter part of the seventeenth century, were transforming the face of material civilization, and of which England was the daring, if not too scrupulous, pioneer.

Infinite growth of material consumption in a finite world is an impossibility.

E. F. Schumacher Quotes