During Blackstone's discussion of the character of an MP, he vents his frustration about the way that MPs who don't know the law make legislation. Whilst doing this he makes an interesting analogy- the law is a book and the MP is a commentator on that book (a bit like I am writing here about Blackstone and have written in the past about Livy and Augustine). Blackstone comments
And how unbecoming must it appear in a member of the legislature to vote for a new law, who is utterly ignorant of the old! what kind of interpretation can he be enabled to give, who is a stranger to the text upon which he comments.Blackstone's analogy is truly radical. When I comment upon a text, I do not seek to alter it. No doubt Blackstone was thinking of the commentators or glossers upon philosophical or biblical texts who would strue the text with comments upon what it did or did not mean. In that sense Blackstone's comments were a more active comment than a modern commentator who separates the text of his comment from that which is commented upon. But even so what this implies is that the law, like the text, does not change- just people's interpretation of that law changes. We here come to a radical division between the common law mind and the modern mind: Blackstone like Coke before him believed that in some sense the law did not change, only our interpretation, our comment on the law changes.