Persistence in research is key; nature reveals its secrets only to those who are patient.

Mastery is not a function of genius or talent. It is a function of time and intense focus applied to a particular field of knowledge.

The first fruit of this imagination - and the first lesson of the social science that embodies it - is the idea that the individual can understand his own experience and gauge his own fate only by locating himself within his period, that he can know his own chances in life only by becoming aware of those of all individuals in his circumstances.