Every mental state exists for a purpose; to understand it, we must ask what function it serves in the broader system of behavior.
每种心理状态都有其存在的目的；要理解它，我们必须询问它在更广泛的行为系统中发挥什么功能。
The end of history will be a very sad time. The struggle for recognition, the willingness to risk one's life for a purely abstract goal, the worldwide ideological struggle that called forth daring, courage, imagination, and idealism, will be replaced by economic calculation, the endless solving of technical problems, environmental concerns, and the satisfaction of sophisticated consumer demands.