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 only thing that is truly important is the difference you make in the world.

农业成功的真正标准是可持续性——在生产力与环境管理之间取得平衡。