In Rational Animals Davidson argues that language is constitutive for thinking, i.e. that thinking requires possessing the notion of thought or belief. This thesis is the point of departure for author's deliberations. He tries to show that on one interpretation this thesis leads to surprising consequences. Even if a child acquires a language, it is possible that he/she doesn't think, because it is not necessary to acquire the notion of thought to possess linguistic abilities. To deal with this difficulty the author suggests that the ability to think be redefined as the ability to manipulate internal representations.