The propensity to truck， barter， and exchange one thing for another is common to all men， and to be found in no other race of animals.
交换、交易和互换的倾向普遍存在于所有人之中，而在其他动物种族中找不到。
商业中唯一不变的就是变化。
The man who does not work for the love of work but only for money is not likely to make money nor to find much fun in life.
"Freedom is nothing but a chance to be better."