Every thought serves some biological purpose.

The stock market is a device for transferring money from the impatient to the patient.

A man is rich in proportion to the number of things which he can afford to let alone. That man is the richest whose pleasures are the cheapest.

释义：通过分析物品的过剩与短缺，就能判断其价值的高低。这句话揭示了市场供求关系对价格的影响。