No one need deny the importance of language to thought and cognition. At the same time, there is a tendency in studies of mind and mental functioning to assume that properties and principles of linguistic, or language-like, forms of representation must hold of forms of thought and representation in general. Consideration of a wider range of symbol systems shows that this is not so. In turn, various claims and arguments in cognitive theory that depend on assumptions applicable only to linguistic systems, do not go through or become difficult to state in a manner that makes them both interesting and plausible.