Monopoly Quotes - page 7
There seem, however, to be two cases in which it will generally be advantageous to lay some burden upon foreign, for the encouragement of domestic industry. The first is, when some particular sort of industry is necessary for the defence of the country. The defence of Great Britain, for example, depends very much upon the number of its sailors and shipping. The act of navigation, therefore, very properly endeavours to give the sailors and shipping of Great Britain the monopoly of the trade of their own country, in some cases, by absolute prohibitions, and in others by heavy burdens upon the shipping of foreign countries.
Adam Smith