This paper seeks to uncover, delineate, 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 interconnected package they have substantial implications. And they constitute a central part of Hart's campaign to put philosophical investigations into 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 some of the 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.
And from the paper:
The four Hartian prescriptions that I have discussed can be summarized as follows:
1. Instead of defining or analyzing terms in isolation, always define or analyze full sentences in which the relevant terms are characteristically used. (The context principle)
2.Distinguish between two kinds of sentences (or statements) -‐-‐ internal and external -‐-‐ in which "rule", "law", "obligation", and other such normative terms are characteristically used.
3. Distinguish between straight and oblique analyses of the internal sentences (or statements) containing "rule", "law", "obligation", etc. by uses of which sentences (or statements) speakers typically express their normative commitments.
4. Distinguish between what is asserted and what is presupposed by speakers who utter internal sentences (or make internal statements).Deeply interesting and characteristically sophisticated. Highly recommended!