These two sections deal with apparently disparate parts of Austin’s theory. The first criticizes Austin’s attempt to construe customary law as a command, and the the second criticizes his use of the idea of habitual obedience in his definition of the sovereign. However, they share a concern for norms beyond, and perhaps more fundamental than, legal commands.

• In reading ch. 3 §3, think how Austin’s idea of a tacit order is supposed to work and why Hart thinks it doesn’t, think about the significance of custom (which is important for Hart’s own positive view), and notice Hart’s summary of the whole chapter’s main points (in a different order) in the next-to-last paragraph (p. 48).

• In §1 of ch. 4, Hart presents one of his criticisms of Austin’s use of the idea of habitual obedience. You should think through the problems that Hart takes the right of succession of sovereigns to raise for the idea of habitual obedience as the basis for sovereignty (there is a summary on pp. 59f). But also think about his discussion of conditions for the existence of rules on pp. 55-57 and about the idea of an “internal aspect” of rules; it will be developed further in later chapters.

We won’t look at the remaining sections of ch. 4. In §2, Hart develops an objection to Austin much like one you saw in Kelsen (p. 55 of his article); and, in the remaining two sections, he considers Austin’s claim that there can be no legal limitation on the power of the sovereign. Hart does not summarize the points made in this chapter as he did in the last, but he states its general moral in the paragraph at the middle of p. 77.