The kind of self-reference which Perlis characterizes as strong, as opposed to formal self-reference which he characterizes as weak, is actually already present in standard forms of formal self-reference. Even if formal self-reference is weak because it is delegated, there is no specific delegation of reference for self-referential sentences, and their ‘self’ part is strong enough. In particular, the structure of self-reference in Godel's sentence, with its application of a self-referential process to itself, provides a model of Perlis’ characterization of (...) a self. This structure can also be interpreted visually, in a way relevant to self and consciousness, namely as self-recognition in a mirror. (shrink)