On the old saw : that may be right in theory but it won't work in practice /
Kant, Immanuel,1724-1804.
Philadelphia, Pa. : University of Pennsylvania Press
[2006?], c1974.
Translation of Über den Gemeinspruch: Das mag in der Theorie richtig sein, taugt aber nicht für die Praxis.
Theory (Philosophy)
Practice (Philosophy)
Ethics.
Law