This paper is a response to two conflicting interpretations of the place of the sociology of knowledge and epistemic relativism in Logical Empiricism: the interpretations put forward by Thomas Uebel (Philosophy of Science 67:138–150, 2000) and David Bloor (The Enigma of the Aerofoil: Rival Theories in Aerodynamics, 1909–1930. Chicago and London: The University of Chicago Press, 2011). I agree with Bloor and Uebel that the sociology of knowledge was a central concern for Frank; and I am convinced by Uebel’s arguments that the same is true for Neurath. I side with Bloor—against Uebel—in maintaining that Frank committed himself to relativism. I try to show the same for Neurath. Still, I disagree with important aspects of Bloor’s rendering of Frank’s relativism.