It is commonly claimed that scientists should hold certain communicative virtues, such as sincerity, openness, honesty and transparency. This paper uses the case of climate science to argue against these claims. Rather, based on a novel account of the range of ways in which non-experts learn from experts (detailed in Section 1), there are reasons to deny that scientists are under any basic obligation to be sincere, honest, open or transparent. Furthermore, not only are these claims analytically confused, they are epistemologically and politically dangerous. Sections 2-4 argue for these claims. The conclusion proposes an alternative standard for ethical communication: that scientists should not engage in “wishful speaking”.