 It is also common to suppose that beliefs play a causal role in the production of behavior. Continuing the example, we might imagine that after learning about the demotion of Pluto, Kai naturally turns his attention elsewhere, not consciously considering the matter for several days, until when reading an old science textbook he encounters the sentence “our solar system contains nine planets”. Involuntarily, his new knowledge about Pluto is called up from memory. He finds himself doubting the truth of the textbook’s claim, and he says, “actually, astronomers no longer accept that”. It seems plausible to say that Kai’s belief about Pluto, or his possession of that belief, caused, or figured in a causal explanation of, his utterance.