The predicate 'be conscious of' is in such a unique situation that the expression 'the consciousness of the consciousness of......of something.' is possible. In this expression each 'consciousness' corresponds to different level of language. First occurrence of this word belongs to the meta-language of the language to which the next belongs. The second belongs to the meta-language of the third, and so on. So long as epistemology pursues all kinds of consciousness, the peculiarity of ' consciousness ' is the same one inherent in epistemology. The language of epistemology has an order and no final mata-language. Because of this peculiarity, the central concept in some branch of this science the self as the ultimate subject of all mental phenomena-becomes fatally obscure. The statement 'The self exists' becomes nonsense.