Quote, John Stuart Mill, 1867

Those branches of politics, or of the laws of social life, on which there exists a collection of facts sufficiently sifted and methodized to form the beginning of a science should be taught ex professo. Among the chief of these is Political Economy, the sources and conditions of wealth and material prosperity for aggregate bodies of human beings....
The same persons who cry down Logic will generally warn you against Political Economy. It is unfeeling, they will tell you. It recognizes unpleasant facts. For my part, the most unfeeling thing I know of is the law of gravitation: it breaks the neck of the best and most amiable person without scruple, if he forgets for a single moment to give heed to it. The winds and waves too are very unfeeling. Would you advise those who go to sea to deny the winds and waves-or to make use of them, and find the means of guarding against their dangers? My advice to you is to study the great writers on Political Economy, and hold firmly by whatever in them you find true; and depend upon it that if you are not selfish or hart-hearted already, Political Economy will not make you so.

(quote taken from macro economics, fourth edition, n. Gregory Mankiw , Worth Publishers, 2000.)