Somewhere around week 2 or 3 of introduction to philosophy, you learn a basic methodological principle in philosophy: When a person offers an argument against or an objection to some position P, you have to ask whether that objection also applies to that person’s own position and their own argument. For instance, suppose some crackpot English professor says, “There is no Truth and no one can claim objective knowledge!” After you’re done laughing, you then point out that by hypothesis, the professor’s claim is not the true, does not describe how things are, and is merely his or her subjective opinion for which she cannot claim knowledge or justification.

In political philosophy, it seems that people frequently fail to ask whether the objections they offer against other positions apply to their own positions. I refer to this as “weaponizing” their principles. They bring up a principle to use a weapon against others, but it does not occur to them to ask whether that principle applies to them and their own ideas. Or, alternatively, it does occur to them, but they don’t take that point seriously.

Here are some examples:

1. Many democratic theorists offer the “demographic objection” against political systems other than democracy. For instance, they will say that a problem with epistocracy is that it might disproportionately empower white and rich people instead of the poor or certain minority groups. However, as I show here, this objection definitely applies to every extant democracy, as all of them empower the rich and ethnic majorities at the expense of the poor and ethnic minorities. In contrast, the version of epistocracy I defend actually fixes the problem.

2. John Rawls happily invokes public choice and motivational problems in the attempt to explain why laissez faire and welfare state capitalism are incompatible with justice as fairness. He invokes the same problems to argue that anarchy won’t work and we need a state. But when someone like James Buchanan then asks about whether his favored system, property owning democracy, will suffer from similar problems, Rawls waves his hand and says he’s doing ideal theory, so he can just imagine people do the right thing for the right reason and always comply with his theory.

3. John Rawls and Samuel Freeman argue that X qualifies as a basic liberty only if it is necessary for (nearly all) people to develop and fully exercise their two moral powers. However, neither Rawls nor Freeman try to show that the things they think are basic liberties actually meet this condition. Instead, Rawls just gestures a bit about how freedom of speech would be useful or helpful toward those ends, and Freeman largely repeats Rawls’s argument. Yet, when John Tomasi parrots Rawls’s exact argument for different conclusions, Freeman then insists on a strict interpretation of the moral powers test, which of course Tomasi’s favored liberties don’t pass.

4. Nearly everyone insists on interpretative charity for criticisms of their own views, but then is happy to attack straw man versions of others’ views. This is probably just hooliganism at play, though.

5. G. A. Cohen argues at great length that mass murder and totalitarian politics characteristic of all real-life socialist societies is not an objection to socialism, because when assessing the justice of socialism, we are supposed to ask how it would work if people were all just and did the right thing. Then, when he criticizes everyone else, he attacks realistic versions of their positions (where he imagines people to have the moral flaws they realistic have) rather than idealized versions.

6. Lots of second-rate hack academics on the Left today spend a great deal of time criticizing libertarians by complaining about where some of them get their research funding. (Some of these hacks even lie about others’ funding sources, accusing them of being funded, for instance, by the Kochs, even when they aren’t.) But they don’t ask whether their own funding sources–including both governmental and from foundations–would also introduce dangers of bias.

7. Internet libertarians, if not serious academic libertarians, often complain that other economic systems are founded on violence. But of course they think that libertarian property rights may be defended with violence. Thus, merely appealing to nonviolence vs violence doesn’t do any work. They need to provide an independent explanation for why people have certain rights and not others.

8. Most public reason liberals, including and perhaps especially Rawls, spend a good deal of their time trying to come up with ad hoc interpretations of the concept of “reasonableness” so that they can just dismiss any criticism of their own positions as unreasonable.

What are some other examples?