Pathology of science occurs when the normal processes of scientific investigation break down and a hypothesis is accepted as true within the mainstream of a discipline without a serious attempt being made to test it and without any recognition that this is happening. It is argued that this has happened in psychometrics: The hypothesis upon which it is premised, that psychological attributes are quantitative, is accepted within the mainstream, and not only do psychometricians fail to acknowledge this, but they hardly recognize the existence of this hypothesis at all. It is suggested that certain social interests, identifiable within the history of modern psychology, have produced this situation because of the ideological and economic secondary gains derived from presenting psychology as a quantitative science. The question of whether modern item response models are exempt from this critique is considered, and it is concluded that they have not yet faced up to the challenges of seriously testing the relevant hypothesis or even bothered to recognize its existence.