This essay aims to critically rethink the relation between the historiographical categorizations provided by the “conflict thesis” and the American controversies on evolution by analyzing the construction of biological and theological discourses which featured the works of Edward Drinker Cope, leader of the so-called “American school Neo-Lamarckism”. As an authority in the American scientific community of the second half of the nineteenth century, Cope set forth a new conceptualization of design in nature based upon the active role displayed by organisms during their life. This assumption, in his own words, implied the reintroduction of theism in nature. Such case study, we argue, represents not only a great testimony of the permeable boundaries which characterized the interaction between scientific and extra-scientific discourses in the 19th century. It also seems to undermine the conflict argument as well as the idea that warfare was the norm in the American reception of Darwinism.