This paper proposes a critical assessment of the concept of “conspiracy theory” as a coherent object of investigation, and evaluates the prospects for an integration of various avenues of research—sociological, epistemological, psychological—that deal with it. Because of the threat posed by conspiracy theories to public health and political stability, academic efforts to understand the sociological and cognitive basis for the adoption of such views, as well as their epistemological flaws, are undoubtedly needed. But the preliminary question of the unity, and of the specificity of the class of things called “conspiracy theories”, is often overlooked. It is addressed in this paper.
Starting from a tentative classification of the various ideations labelled “conspiracy theories”, we then focus on a particularly important subclass thereof, namely those promoting anti-scientific views. From this, we draw a first, sceptical conclusion as to the existence of a clear-cut boundary between conspiracy thinking and healthy rational critique of science (both sociological and philosophical). This leads us to evaluate the attempt of analysing conspiracy theories’ epistemic flaws in the light of philosophical standards for scientific theories. Having shown that this route is a dead-end, we highlight what appears as a major divide among philosophical and psychological accounts of CTs, namely whether one should treat them as irrational, or as merely wrong (in the latter, rationalist approach, CTs would just be wrong statements resulting from rational operations). Focusing again on anti-science CTs, we finally argue in favour of a politically and socially contextualised approach to the growth and spread of conspiracy ideations, over a scheme considering CTs as abstract entities, independently from the socially situated agents who hold them.