Before reading my ill-informed opinions you'll want to read others. keepcalmtalklaw says it argues that law, and its modern fixation on rights and due process, has now largely filled the space previously occupied by politics and political debate - for better or for worse3. Or you can read Stephen Sedley in the LRB, who seems to disagree with Sumpers a lot; perhaps professional enmity or just the desire to have something to say, I don't know, I got a bit bored reading him5. Anyway, enough of these other people, "what of me?" I hear you cry.
Chapter 1: Law's expanding empire
The law used to regulate religion, and ban homosexuality. Now it regulates neither, and indeed bans discrimination. Animal welfare legislation, by banning fur farming on moral grounds, has enforced a common morality: what could have been an entirely personal moral decision, to purchase and wear fur or not, has been made common (he declines to argue the rights and wrongs of fur; as he does for other things; this is correct; his discussion is not over the rights and wrong of these choices, but whether they should be covered by law). This leads me to reconsider his point re non-discrimination: the law could have simply withdrawn from the area, but did not; it chose to ban discrimination. Per Gay Cakes I think the answer is that the law should ban discrimination by the govt (ideally in the glorious words of the US constitution:
A little later he asserts that the advance of law into ever more areas is simply a fact, which we shall have to get used to. It is certainly an observed fact of recent times, but not quite the fact-of-nature that he appears to consider it; perhaps it is not an area he wishes to discuss so closes it as quickly as possible.
After morality, he considers risk, and notes that we become ever more risk averse and insist on the law protecting us, at the inevitable cost to our liberty.
Chapter 2: In Praise of Politics
By constantly disparaging pols I may have given the impression that I disparage the concept of the political process, but this is not true; see for example Aristotle's Politics. JS, while aware of political failings and the public's opinion of pols, nonetheless notes the importance and elusiveness of the concept of "legitimacy": people will accept decisions they disagree with as long as they accept the legitimacy of the decision-making process.
But it is necessary to counter the tyranny of the majority; JS asserts two parts to this: representative democracy, and law.
JS's defence of RD is not convincing to me. Chiefly, it is that it is superior to direct democracy (which is just-about-now just-about-possible1) because pols are less likely to sacrifice the long-term good of the country to short-term interests. In asserting that we use RD as a matter of principle, he ignores the obvious, that current pols would fight tooth and nail to keep their jobs and power, and that any change would have to come through them, the most opposed to change. SJ acknowledges this view as perhaps "elitist", but not his own bias for it as a member of the elite. He then goes on to defend political parties, on the grounds that they are flexible and balance interests. Since this is all in the context of Brexit, he has to bring that in, and finds himself obliged to say that "Europe has become the defining issue which determines party allegiance". This is nonsense. Brexit cuts across party allegiances.
We move on to law; but almost immeadiately return to the prior theme, of increasing, umm, activity of law in the political process, or "law as the continuation of politics by other means" (a familiar idea from the USAnian climate change cases). As far as I can tell nowhere does Sumpers admit the obvious conflict of interest here: judges are awarding themselves more power. Briefly, he touches on the appointment of judges in the UK. They are nominally nominated by an independent panel. But actually this just means they are nominated out of public site by an opaque process. JS appears opposed to something similar to the USAnian political appointment process, but admits that with judges becoming more political, this may be inevitable2. But then we get to the more interesting point: that judges are intrinsically unable to mediate; that it is a zero-sum game; and cannot accommodate diverse opinions the way politics can (if it works well). This point is a good one, but only quasi-true. Reading the deliberations of the SCOTUS (I recommend Scotusblog) I think it becomes clear that in many cases the judges are trying to strike a balance, and will only come down hard on one side if given no choice.
Chapter 3: Human Rights and Wrongs
Human rights have a long common-law foundation, but there is an awkward problem of definition; what exactly are they? I like Hobbes's view (see wiki) which I assert the USAnian constitution largely subscribes to: that "rights" are things you have naturally, that laws constrain those rights by imposing obligations, and that the constitution imposes restrictions on the state as to what constraints it may impose. Thus the first amendment says Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; and does not state that people have the right to freedom of religion or a right to freedom of speech; and I strongly criticise the European approach, which is to award people rights by writing them down on pieces of paper. Anyone with any knowledge of the USAnian constitution will of course object that they do not everywhere follow the wise model of the above words; and I can only reply that no-one is perfect.
JS's issue is the public concern that HR law is independent of democratic choice, and protected against amendment by a democratic legislature; or equivalently that HR law has exceeded it's proper sphere and trespasses on politics.
Shifting over to the ideal domain, JS notes that democracies can enact what rights they want; if there is to be some over-arching HR, then that requires some legitimacy; otherwise, HR are just whatever your law currently defines. Once, religious authority might have supplied that legitimacy; no more. Some rights can be considered fundamental, because without them society as we desire it cannot exist; equality before the law, freedom of speech.
What he doesn't say explicitly is something I've said before: that there's a problem in the gap between "rights" which sound excellent when considered in their prime formulation, and the consequences that flow from them4. He does however implicitly consider this, because we move onto...
We then get a lot of technical stuff about the structure of HR legislation, which I think you should read from him not my poor paraphrase; but cutting to the chase we end up with extensions of the text which rest on the sole authority of the judges of the Strasbourg court. This is, in reality, a form of non-consensual legislation... most of the rights which the S court has added to our law are quite unsuitable for inclusion in any HR instrument. We're back to legitimacy, and the problem of taking difficult and disputed decisions out of the political (i.e. public) sphere and "privatising" them (that's my phrase, not his) by calling them matters of law. This is correct, and accounts for much of the public discussion' which discussion is not, of course, on these rarefied terms; and part of the public anger is I think at it's inability to articulate it's unease.
Chapter 4: Lessons from America
The primary lesson is that he isn't too keen on a constitution, for reasons I find unconvincing. He does note that the SCOTUS has made some rather broad and arguably bad decisions: finding a right to privacy (which underlies Roe vs Wade) and Dred Scott. Otherwise, we're left with judges not being able to save society single-handed, which is or should be uncontroversial.
Chapter 5: Constitutions, New and Old
Spends most of its time arguing against changing to a written constitution, which is pointless, because that's not going to happen. Does the familiar bemoaning the decline in citizen participation in politics, but finds nothing new to say on the subject. Argues against PR, pointlessly; and of course I disagree. So I'm glad to be able to some extent to regain my prejudices against him in this last chapter.
Update: on reflection
On reflection, prehaps I was close tothe truth when I said "enchanted" and perhaps I should have said "bedazzled". I feel there is somehow less ot this than meets the eye, as exemplified by my failure to find any "key points" to pull out. Except I still like his point re legitimacy.
1. Note, this doesn't mean clumsy referenda. It would mean internet-based voting on a far more regular basis. It is not going to happen, so carefully considering the exact details is pointless.
2.See-also the timely Boris Johnson takes on the judges, and Why pruning the British judiciary’s powers will prove tricky from the Economist.
3. And this is wrong, because the thinks it is for worse.
4. I'd suggest some kind of "back flow": if you can reason from your universal rights to a decision that is wrong, then (assuming your reasoning survives scrutiny) you have to reconsider what you think of as rights. "wrong" here might be slippery. JS makes a good point in that if it is a question of morality, and you assert universal rights, then significant rational disagreement amounts to it being in error.
5. Re-reading SS I retain the same antipathy; for example, in 2011... attacking the judiciary of which he was now a member for methodically invading the territory of politics... he has returned to the theme of the deference owed by law to politics. It is his bad luck to have done so at a moment when the UK’s political process, both in and outside Parliament, has been in functional meltdown and moral decline, while both his own court and the lower courts have remained a source of constitutional principle and political stability. I think this misses the point; that adverse-to-politics judicial decisions are part of the political problem.