Prof. Post was one of my favorite professors at Temple Law. At Volokh, he notes what strikes many as problems with the kind of originalism Justice Thomas articulates:
In support of this latter proposition—which, more or less, ends the constitutional inquiry for Justice Thomas—he relies, inter alia, on Wadsworth’s “The Well-Ordered Family” of 1712, Cotton Mather’s “A Family Well-Ordered” (1699), “The History of Genesis” (1708), Locke’s “Some Thoughts Concerning Education” (1692), Burgh’s “Thoughts on Education” (1749), along with a number of more recent scholarly studies focused on child-rearing practices during the Founding period.
That is originalism on steroids, and, to my eye, rather poignantly illustrates the weakness of the approach. I understand, and am sympathetic to, the notion that the meaning of a constitutional provision should be informed by the meaning given to it by those who drafted and ratified it. But can that really mean that we will look to the child-rearing principles of Cotton Mather and John Locke to define, for all time, the scope of the constitutional protection for free speech? Even assuming that Justice Thomas (or anyone else) can reconstruct the sociology of the eighteenth century to definitively support the notion that parents possessed “absolute authority” over their children, and that “total parental control over children’s lives” was the governing societal norm—what then? The question in this case is not “do parents have absolute authority over their children?” The question in the case is, rather, “how does what the state did here relate to (a) the authority of parents over their children, (b) the power of the state to protect the well-being of children, and (c) the constitutional protection for ‘the freedom of speech’?” That’s a hard question in 2011, and it would have been a hard question in 1791, because it involves categorization: Is this, actually, a case about the authority of parents over their children? Or is it a case about the extent of the state’s power to protect minors? The scope of the First Amendment rights of video game manufacturers? Or the scope of the First Amendment rights of minors? ....
I'd like to see Prof. Post get more involved in the, "what kind of originalism is valid originalism" dialog with among others Randy Barnett, Akhil Amar, and Lawrence Sollum.