A monarchy, in other words, lends to a political order a vital element of continuity that enables gradual reform. The rule of law is thus guaranteed by respect for authority — as Dr. Johnson advised Boswell: “Now, Sir, that respect for authority is much more easily granted to a man whose father has had it, than to an upstart, and so Society is more easily supported.”

Their contemporary, the historian Edward Gibbon, weighed the rival systems and came down with characteristic acerbity in favor of a hereditary sovereign. “We may easily devise imaginary forms of government, in which the sceptre shall be constantly bestowed on the most worthy, by the free and incorrupt suffrage of the whole community,” he wrote, but “experience overturns these airy fabrics.”

The advantage of monarchy is that the institution “extinguishes the hopes of faction” by rising above the toxic partisanship of competing parties and vying elected officials. “To the firm establishment of this idea,” Gibbon concluded, “we owe the peaceful succession, and mild administration, of European monarchies.”

It may be remembered that no British monarch has been assassinated for about five centuries, while no fewer than four American presidents have been murdered in the last 150 or so years. A factor to ponder, I suggest.