"Much has been made of the principle, in England and America, that international law is part of the national law to be applied by national courts in appropriate circumstances. As Mr. Justice Gray has expressed it, in the Paquete Habana: 'International law is part of our law, and must be ascertained and administered by the courts of justice of appropriate jurisdiction, as often as question of right depending upon it are duly presented for their determination...'
This principle is useful, where it is applicable, but it is subject to limitations which are sometimes inadequately appreciated ..."
Dickinson, Edwin D. "International Political Questions in the National Courts." Am. J. Int'l L. 19 (1925): 157–63.