In this article, I discuss various substantive and methodological issues in jurisprudence, prompted by Neil MacCormick's views in Part 4 of his Institutions of Law. I begin by surveying some contemporary legal theoretical views on whether bad law is still, or is really, law, before moving on to compare John Finnis' and Neil MacCormick's views on this question, and on related methodological issues. I attempt to develop and begin to defend a position wherein although it is necessary to understand law's aims, and the values which it ought to realise in order properly to understand its nature, the failure to achieve those aims or to realise those values does not thereby render something less than fully law.