"AIDS denialism is one of several incarnations of denialism. All denialism is defined by rhetorical tactics designed to give the impression of a legitimate debate among experts when in fact there is none. Holocaust deniers claim that historians disagree about the evidence for Nazi mass gassings and systematic murder of Jews. Global warming denialists say that climatologists are torn by the evidence about climate change. 9/11 “Truth Seekers”, as clever a piece of branding as “pro-life”, say the collapse of the Twin Towers resulted from controlled demolition. Vaccine hysterics tell us that the science is split on whether vaccinations cause autism. And AIDS denialists say that scientists are in disagreement about whether HIV causes AIDS."