Let’s start with the obvious. A reactionary—i.e., a right-winger—is someone who believes in order, stability, and security. All of which he treats as synonyms.
Think, as a progressive, about the simplicity of this proposition. It is so stupid as to be almost mindless. What is the purpose of government? Why do we have government, rather than nothing? Because the alternative is Corner Man.
Note that Corner Man has his own philosophy of government. He exercises sovereignty. That’s his corner. (“Metro [the Las Vegas PD] can’t even get me off this ---- corner.”) Indeed, he has much the same relationship to the government that you and I know and love, that Henry VIII had to the Pope. And how did he acquire his corner? “I’ve been on this ---- corner for ten ---- years.” In legal theory this is called adverse possession, which is more or less how the Tudors acquired their little island.
Of course, we reactionaries are not fans of Corner Man, largely because his claim to the corner is contested by a superior authority which will prevail in any serious conflict. Why does he attack the blue PT Cruiser? Is it because he’s on crack? Perhaps, but perhaps it’s also because the driver owes allegiance to the other side of the conflict—“Metro”—and neither has nor would acknowledge Corner Man’s authority. For example, she has not paid him any taxes, fees, or rents for the privilege of positioning her vehicle on his (so-called) territory.
One synonym for reactionary is legitimist. When the legitimist asks whether Corner Man really owns his corner, he is not asking whether Corner Man should own his corner. He asks whether Corner Man does own his corner. And his answer is “no.” He prefers the claim of “Metro,” not (or not just) because “Metro” is not in the habit of getting loaded and bashing the holy heck out of random peoples’ cars, but because “Metro” and Corner Man have conflicting claims, and in the end, the former is almost certain to win.
And when he asks whether the Bourbons are the legitimate rulers of France or the Stuarts of England, he is not asking whether (a) the Bourbon or Stuart family has some hereditary biological property that makes their scions ideal for the job (midichlorians, perhaps), or (b) the Bourbon or Stuart will suffer intolerably as a result of being deprived of the throne, or even (c) the Bourbon or Stuart families obtained their original claims fairly and squarely. At least, not if he has any sense. None of these arguments is even close to viable.
Thus, the order that the rational reactionary seeks to preserve and/or restore is arbitrary. Perhaps it can be justified on some moral basis. But probably not. It is good simply because it is order, and the alternative to order is violence at worst and politics at best. If the Bourbons do not rule France, someone will—Robespierre, or Napoleon, or Corner Man.