Constitutional orthodoxy views the courts as interpreters of the Constitution with no power to amend it or to invalidate laws which were valid when enacted. Combined with the claim that a document's meaning is fixed at the date of drafting, it provide powerful arguments against judges innovating. However, it suffers from two weaknesses. Firstly, it is irrelevant in cases where the Constitution does not provide an answer. Secondly, it rules out all innovation. The article considers whether concept-conception distinction can alleviate these weaknesses, firstly, by reducing the number of cases in which the Constitution does not provide an answer, and secondly, allowing some evolution consistently with the claim that the meaning ofthe Constitution is fixed. The article concludes that the distinction does little to reduce the number of cases in which the Constitution does not provide an answer because Dworkin's right answer thesis, which is often associated with it, is not part of its internal logic. The distinction also does not show how the Australian Constitution can evolve because it is only relevant to the interpretation of contested concepts, which are typically values such as those found in bills of rights, and is not relevant to the interpretation of general terms in which most of the Australian Constitution is drafted.