The writer must be a witness to his time.

The method of psychology must be as exact as that of the physical sciences.

最成功的企业是那些倾听客户并迅速适应的企业。

The present state of the system of nature is evidently a consequence of what it was in the preceding moment, and if we conceive of an intelligence which at a given instant comprehends all the relations of the entities of this universe, it could state the respective positions, motions, and general effects of all these entities at any time in the past or future.