Although in his phenomenology Husserl puts the external world into brackets (i.e. does not appeal to it, or its parts, in any explanation of the phenomenological properties of mental acts and their contents), still, he does not doubt its existence. He does not claim that mental acts do not refer to the actual (in his sense) world; he only claims that those mental experiences that do refer to the world must be described by 'intra-mental' means, without appealing to any things in the external world.