One of the ironies of our time is that economists have been discovering the importance of law, as such -- as distinguished from the specific merits of particular laws -- while judges seem increasingly to be losing sight of the rule of law.
"I can hardly imagine any laws so bad, to which I would not rather be subject than to the caprice of a man," John Stuart Mill said more than a century and a half ago.
Modern economists usually have in mind the economic advantages to a society of having a framework of known, enduring, and dependable rules -- the rule of law -- within which economic activities can be planned and long-term commitments and investments can be made. But Mill saw the benefits of living under known rules to extend far beyond economic benefits.
Mill spoke of the danger of having to lead "a life of anxiety lest by some of my acts I should unwittingly infringe against a will which had never been made known to me." Some of today's vague and ambiguous anti-trust, anti-discrimination, and environmental laws strike like lightning out of the blue to hit people who had no idea that they were doing something wrong.
The Constitution of the United States expressly forbad retroactive laws -- "ex post facto" laws, it called them -- but judicial decisions creating new rights, duties, and nuances out of thin air are for all practical purposes ex post facto law.
"Evolving standards" are also ex post facto law, for who can know in advance how someone else's standards are going to evolve, much less which evolving standards will get a majority of the votes in the Supreme Court?
The recent practice of using foreign laws as bases for judicial decisions about American laws likewise turns law into the caprices that John Stuart Mill feared more than he feared bad laws.
There is no such thing as generic foreign law. There are the specific laws of France and the very different specific laws of Saudi Arabia and of hundreds of other countries around the world. It is a matter of individual prejudice or caprice which of these laws any given judge chooses to cite.
Justice Anthony Kennedy, for example, referred to foreign laws as a reason for declaring an American state's law unconstitutional because it permitted the execution of murderers who were not yet 18 years old, which some foreign governments do not. In other words, laws enacted by the elected representatives of an American state can be wiped out if people in Spain or New Zealand think otherwise.