Abstract
I argue that scientism in general is best understood as the thesis that the boundaries of the natural sciences should be expanded in order to include academic disciplines or realms of life that are widely considered not to belong to the realm of science. However, every adherent and critic of scientism should make clear which of the many varieties of scientism she adheres to or criticizes. In doing so, she should specify whether she is talking about (a) academic or universal scientism, (b) reductive, methodological, epistemological, ontological, moral, or existential, scientism, (c) full or partial scientism, (d) strong or weak scientism, and (e) in the case of moral and existential scientism: replacement or illusion scientism. The strongest version of scientism one could defend is a conjunction of the following theses: strong full epistemological scientism, strong full ontological scientism, strong full Illusion-moral scientism, strong Illusion-existential scientism, and strong full reductive scientism. After a detailed discussion of each of the main varieties of scientism and their interrelations, the paper provides a conceptual map, consisting of two figures, which displays the main varieties of scientism and the relations that obtain between them, primarily, those of implication and mutual exclusion.