This portion of labour which is used to meet an aim cannot be, at the same time, devoted to another.

Frédéric Bastiat
Complete Works, Volume 3, pages 449 to 458 (in French)
Libre-Echange, November 7th, 1847

Pages 437 to 448 in volume III are a note from the editor under the title End of the First Campaign of the League in which he describes the way the repeal of the corn laws passed in parliament and the suspension of the activities of the Free-Trade League. I do not extract any quote from it.

The article published in Libre-Echange on November 7th, 1847 pertains to the need to keep on progressing on free trade. Frédéric Bastiat identifies four reforms that England will have to pursue as a logical follow-up to the repeal of the corn laws and the end of mercantilism, viz. the end of colonialism, the end of diplomatic intervention, the repeal of the navigation laws and the reduction of the army. He explains in details the reasons why mercantilism is a source of conflict and why its opposite, free-trade, is a source of peace. We find here his first motivation about free-trade, viz. to promote peace in the world.

Today’s quote is part of his argument in favour of reducing the size of the army and navy. What is said here is that the ressources that are used up for it cannot be used for economic growth and the well-being of the people. Since the coming reforms will reduce the offensive and defensive needs of the United-Kingdom, reducing the weight of the army will not only be possible but also desirable because it will allow to allocate productive ressources to increasing the wealth of the country. We find here a major concept of economic science, which consists in considering production means as scarce ressources that need to be allocated as best as possible in order to increase prosperity (this is the principle of trade-offs to which an opportunity cost is associated).