Toh, K. (2014). Four Neglected Prescriptions of Hartian Legal Philosophy. Law and Philosophy, 33, 689–724. doi:10.1007/s10982-013-9203-4
[Abstract]This paper seeks to uncover and rationally reconstruct four theoretical prescriptions that H. L. A. Hart urged philosophers to observe and follow when investigating and theorizing about the nature of law. The four prescriptions may appear meager and insignificant when each is seen in isolation, but together as an inter-connected set they have substantial implications. In effect, they constitute a central part of Hart's campaign to put philosophical investigations about the nature of law onto a path to a genuine research program. The paper takes note of certain prevalent and robust trends in contemporary legal philosophy that detract its practitioners from the four prescriptions, and that have them revert to the some older modes of thinking from which Hart sought a decisive break. A number of contemporary legal philosophers' views and commitments are taken up and assessed, and in particular those of John Gardner and Leslie Green.
Note:
See also Toh, K. Erratum to: Four Neglected Prescriptions of Hartian Legal Philosophy. Law and Philos 34, 333–368 (2015). https://doi.org/10.1007/s10982-015-9226-0
[Citing Place (1956)]  
Citing Place (1956) in context (citations start with an asterisk *):
Section III. THE CONTEXT PRINCIPLE
* When many contemporary legal philosophers say that, according to Hart, rules are practices, they could be attributing to him an analytic claim about the meaning of ‘rule’, or an a posteriori, metaphysical claim about what rules are. Hart was writing contemporaneously with philosophers like Place (1956) and Smart (1959) who were beginning to distinguish between analytic claims and metaphysical claims of identity in the context of the mind–body problem – between ‘the ‘‘is’’ of definition’ and ‘the ‘‘is’’ of composition’, as Place puts it. But Hart seems consistently to have overlooked the distinction. He seems to treat all noncontingent claims as analytic claims. Footnote 3: Place and Smart treated the relevant identities as contingent, a position that was later challenged by Kripke (1972/1980).