I am a very bad example though, for one because English is just my second language. Sure there is thinking before words are learned. Language is a complicated problem to talk about, just like self awareness. Consciousness is a very nebulous term to me. Still, you'd have to prove that language is theoretically unfit. Any such logic might be incomplete if you suppose you cannot put it into words. A complete first order logic is expressible however, following Goedels completeness theorem.