… is from David Hume’s 1742 essay “Of the Balance of Trade” (here from pages 309-310 of the 1985 Liberty Fund collection of Hume’s essays, edited by the late Eugene Miller, Essays: Moral, Political, and Literary):
But there still prevails, even in nations well acquainted with commerce, a strong jealousy with regard to the balance of trade, and a fear, that all their gold and silver may be leaving them. This seems to me, almost in every case, a groundless apprehension; and I should as soon dread, that all our springs and rivers should be exhausted, as that money should abandon a kingdom where there are people and industry. Let us carefully preserve these latter advantages; and we need never be apprehensive of losing the former.
DBx: It is truly a shame that “this whole doctrine of the balance of trade” – a doctrine unsalvageably absurd – was not long ago cast where it belongs, namely, into the towering trash heap of the many cockamamie notions that people, throughout history, once clung to.


But there still prevails, even in nations well acquainted with commerce, a strong jealousy with regard to the balance of trade, and a fear, that all their gold and silver may be leaving them. This seems to me, almost in every case, a groundless apprehension; and I should as soon dread, that all our springs and rivers should be exhausted, as that money should abandon a kingdom where there are people and industry. Let us carefully preserve these latter advantages; and we need never be apprehensive of losing the former.
