A leader's job isn't to have all the answers, but to ask the right questions.

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.

The traditional disputes of philosophers are， for the most part， as unwarranted as they are unfruitful.