Propositions and reasoning in Russell and Frege

Both Russell and Frege were inclined to think that there is nothing essentially linguistic about thought: any actual reliance of ours upon language is a mere psychological contingency. If so then it should be possible to formulate logic in such a way that logical relationships are not represented or expressed as principles pertaining to linguistic forms. Russell and Frege take pains to achieve this, but fail. I explain this by looking at some features of Grundgesetz and Principia. Their failure, I suggest, is due to the nature of the case.
Bertrand Russell and Gottlob Frege believed thought existed independent of language, and that reliance on language was nothing more than psychological contingency. If that is true, logic could be formulated so that logical relationships do not depend on expression as principles requiring linguistic forms. Russell and Frege erred in their reasoning, due primarily to the nature of the case.