The difference between the most dissimilar characters, between a philosopher and a common street porter, for example, seems to arise not so much from nature, as from habit, custom, and education.
Adam SmithWhat can be added to the happiness of the man who is in health, who is out of debt, and has a clear conscience?
Adam SmithThe natural effort of every individual to better his own condition is so powerful that it is alone, and without any assistance, capable not only of carrying on the society to wealth and prosperity, but of surmounting 100 impertinent obstructions with which the folly of human laws too often encumbers its operations.
Adam Smith