According to Noam Chomsky, as described in "Of Minds and Language" (2009), the thought puzzle arises because of extreme externalism: the assumption that what is true in our minds is true in the world. This is not an unassailable assumption, from the perspective of the natural sciences, because human intuition is often mistaken. Cognitive science would treat this thought puzzle as the subject of an investigation of the human mind. Studying this human confusion can reveal much about the brain's operation, but little about the nature of the human-independent external world.