 Now it is unclear why Frege thought that he could answer the question posed here by saying that we apprehend numbers as the extensions of concepts. He seems to think we can answer the obvious next question “How do we apprehend extensions?” by saying “by way of Basic Law V”.   His idea here seems to be that since Basic Law V is supposed to be purely analytic or true in virtue of the meanings of its terms, we apprehend a pair of extensions whenever we truly judge that concepts \(F\) and \(G\) are materially equivalent. Some philosophers do argue that certain consistent principles having the same logical form as Basic Law V are analytic, and that such principles justify reference to the entities described in the left-side condition by grounding such reference in the truth of the right-side  condition.[15]