Today, “scientism“ is a concept with a negative connotation in every language. Although many definitions are circulating, they have the assessment in common that scientism implicates a blind faith in science, which is wrong, simple-minded and even dangerous. However, the question is, who actually is defending that kind of position? Is scientism not just a ghost, a projection, an intellectual scarecrow in order to use many people’s fear of science in order to bash rationalistic opinions? This article develops the argument (...) that scientism is a real historical current which can be analyzed in a concrete way. It starts by outlining the history of the French word “scientisme” and the debates around it and discovers that the word is not at all of recent invention, but goes back to the 1840s and received its negative emphasis in the late nineteenth century when “scientific spiritism” on the one hand and Catholicism on the other were struggling against the “exaggerated” claims of natural science. A polemical counter-concept was therefore needed. Soon afterward some scientists and philosophers emerge, like Félix Le Dantec, Abel Rey or Marcel Boll, who turn around the invective in order to describe their own optimistic and rationalistic conception of science. In conclusion the article argues that scientism has to be understood as an intellectual project and as an optimistic thought-style in science that does not at all correspond to the prejudices of the amoral scientist or the power-hungry technocrat, but is represented mostly by outsiders and nonconformists. (shrink)