The popular notion of bullshit and the term that expresses it has received little philosophical attention despite the fact that it pervades much of human discourse. Frankfurt recovered bullshit analysis in the eighties and opened the way to studies on its nature and function. Our interest in bullshit is philosophically analytical, but also practical, as bullshit particularly affects the field of science policy. In order to understand that double character, we first present Grice’s model of meaning of expressions and then (...) summarize the controversy between the tobacco industry and the US Administration, which allows us to state our basic hypothesis: tobacco companies have developed and implemented a discursive tactic of bullshit in order to delay or avoid governmental regulations and decisions. Before eventually applying the Gricean model to various cases of bullshit, we locate our approach against the background of the comparison between sound and junk science. Keywords: Grice, intention, meaning, tobacco industry, bullshit, junk science, uncertainty. (shrink)