The work of the late nineteenth-century American geologist-geographer, Nathaniel Southgate Shaler, on the conservation of natural resources is explored within the context of the conservationist-preservationist debate. In attempting to hold elements from both these perspectives in balance, his transitional stance demonstrates that eclecticism which gives his work its distinctive character. In addition to his specific proposals regarding forest and soil management, hydrological regulation, and energy supply, his desire to disseminate conservationist principles by educational, spiritual and political commitments, reveals an attempt to evolve a comprehensive environmental ethic. Neglect of his ideas seems to reflect the continuing tension between those romantic and scientific attitudes to nature which he sought to synthesize in his use of the concept of the humanized landscape. Another American, Nathaniel S. Shaler, was an outstanding figure in the last quarter of the nineteenth century because, like Marsh, he looked at conservation from a world point of view and because he was interested in so many phases of the subject. (Clarence Glacken, 1956) Les etudes ulterieures ont montre qu'il fallait joindre au nom de Marsh celui d'un autre precurseur, Nathaniel Southgate Shaler: ce geologue est surtout connu des geographes parce qu'il avait su remarquer les qualites de William Morris Davis, dont il fit son assistant i Harvard. On oublie son ouvrage: Man and the Earth... dans lequel il developpe le theme de la conservation des ressources naturelles. (Paul Claval, 1976) DESPITE the plethora of historical reviews of the development of conservation awareness in late nineteenth-century America, the significance of the contribution made by Nathaniel Southgate Shaler (1841-1906) has been largely ignored. While a few, isolated comments, punctuating these general histories, represent him as a precursor of the conservation movement, most fail entirely to do justice to the comprehensiveness and eclecticism of his work. Belonging to a generation caught between two sets of values, one old and one new, he had an inability, indeed unwillingness, wholly to embrace or to repudiate either, which must surely be regarded as crucial to any interpretation of the complex, historical evolution of modern ecological consciousness. Indeed an elucidation of Shaler's writings on conservation leaves one with a feeling of dejd vu, for his comments on wilderness preservation for transcendental-spiritual ends are echoed in modern romantic calls for environmental awareness (Reich, 1970; Brand, 1971) and the rejection of mechanized society (Ellul, 1964; Mumford, 1966), while the countervailing scientific response to the demands of a conservation economy finds its parallel in the sophistication of contemporary environmental science (McIntosh, 1976). Those diverse traditions of Western environmental thought (Passmore, 1974) which have produced these two anachronistic, because exclusive, standpoints, mystic naturism (Darling, 1969; Roszak, 1971) and quanti-