Von Liebig was quoted by Marx who, in my view could be counted among the environnementalists. This point is developped in a paper coauthored with Ms Ferrari and H. Hanusch (Augsburg University, prepared for the Georgescu-Roegen Conference, Strasbourg, November 1998 Marx, Schumpeter and Georgescu-Roegen : Three conceptions of the evolution of economic systems? " The paper can be downloaded at http://lirhe.univ-tlse1.fr/publications/notes/385-04.pdf Alain Alcouffe