经济的活力在于其持续适应和创新的能力。

在任何情况下都要寻找积极的一面。

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.

在数学中，提出问题的艺术必须比解决问题更有价值。

The improvement of understanding is for two ends: first, our own increase of knowledge; secondly, to enable us to deliver that knowledge to others.