In the years of the post-Darwinian debate, many American naturalists invoked the name of Lamarck to signal their belief in a purposive and anti-Darwinian view of evolution. Yet Weismann’s theory of germ-plasm continuity undermined the shared tenet of the neo-Lamarckian theories as well as the idea of the interchangeability between biological and social heredity. Edward Drinker Cope, the leader of the so-called “American School,” defended his neo-Lamarckian philosophy against every attempt to redefine the relationship between behavior, development, and heredity beyond (...) the epigenetic model of inheritance. This paper explores Cope’s late-career defense of neo-Lamarckism. Particular attention is dedicated to the debate he had with James Mark Baldwin before the publication of Baldwin’s own “A New Factor in Evolution”. I argue that Cope’s criticism was partly due to the fact that Baldwin’s theory of social heredity threatened Cope’s biologistic stance, as well as his attempt to preserve design in nature. This theoretical attitude had a remarkable impact on Baldwin’s arguments for the theory of organic selection. (shrink)

It is common to designate Lamarck and Lamarckism as the main historical references for conceptualizing the relationship between organisms and the environment. The Lamarckian principle of the inheritance of acquired characters is often considered to be the central aspect of the “environmentalism” developed in this lineage, up to recent debates concerning the possible Lamarckian origins of epigenetics. Rather than focusing only on heredity, this article will explore the materialist aspect of the Lamarckian conception of the environment, seeking to highlight that (...) the life-supporting function of physicochemical milieux was its cornerstone. Indeed, compared to the Darwinian conception of the environment, which focuses on interindividual and interspecific relationships in a given habitat, Lamarck’s emphasis on the dependencies of organisms on physicochemical environments appears to have given rise to a very active philosophical environmentalism. Studying the environmental Lamarckism of 19th-century philosophers and social scientists in France, Great Britain, and the United States, such as Comte, Quatrefages, Spencer, and Ward, I propose to analyze their contribution to the conceptualization of the environment. The social, moral, or psychological conceptions of human environments that proliferated in the second half of the 19th century deviated from Lamarck’s more material approach, but they were still referencing Lamarck. Examining the scope of their “Lamarckism,” this article seeks to highlight the common context of life sciences and social philosophy, in which the environment emerged as a central issue in the 19th century. (shrink)