Libertarians hear this sort of thing a lot. “You don’t think there should be limits on campaign spending? Then you must want corporations to buy elections!” Or, “You’re opposed to public schooling? What, you think all our children should just stay ignorant?”

We call this a false dilemma, a well‐​known logical fallacy. A person commits it when he limits the available choices in an argument too much. You can pick between A or B, he says, when in fact there’s an option C (and D, E, and F), as well. For Maher, either we keep Medicare and Society Security or we allow horrific poverty.

The false dilemma’s a logical fallacy for good reason and so by itself is never a good argument against, well, anything. But that doesn’t mean we should just ignore it. Instead, once we’ve noticed how many people employ false dilemmas against libertarian proposals, we should take a moment to ask why.

I submit that the false dilemma’s prevalence results in part from the way many libertarians talk about, and argue for, their political views.

If you have no reason to think options exist beyond just A and B, then if you hear someone arguing strongly against A, it’s not stupid to assume he’s either in favor of B or at least prefers B to A. So if you aren’t aware of any ways to prevent destitution besides Social Security, and you hear a libertarian arguing strongly against the morality of Society Security, then it’s rather likely you’ll conclude that he either wants destitution for the poor or at least would rather see the poor destitute than suffer the moral harm of Social Security.

Libertarians bear some of the blame for this. Quite often when choosing our rhetoric, we have a tendency to focus on “not A” instead of saying, “B’s not good either, so let’s instead do C.” For example, folks on the left are less likely to attack us with false dilemmas if we focus not so exclusively on the rights violations inherent in paying for Social Security, but instead point out that Social Security doesn’t work all that well or efficiently if the goal is to prevent destitution, and then offer better alternatives.

This “not A” tendency could result from the simple fact that offering alternatives means having persuasive alternatives in mind. And while they’re myriad, not all of us have the time or inclination to learn them. Call it a kind of rational ignorance in political debate. Far easier to just apply a single principle, a “universal acid” as Daniel Dennett calls it.

But we’re often also motivated by a desire to maintain our principles. Principles are good, of course. That libertarians say we value freedom and mean it is a crucial difference between us and conservatives and progressives. On the other hand, we need to recognize that non‐​libertarians don’t accept our core principles. If they did, they wouldn’t be non‐​libertarians. So if our goal is not just to be right, but to be persuasive, then starting with common ground can be rather more effective. Yes, we take a principled stand against the state coercion behind Social Security, but we also don’t want people to suffer from rampant poverty. In fact, much of what’s appealing about libertarianism is that it’s a genuine path to both: we can be free and prosperous. We shouldn’t water down our libertarianism but we should pay attention to when leading with the argument from prosperity–and using it as a way to then persuade on the issue of freedom–can be more effective than making only the argument from freedom.

Bill Maher’s fulmination just shows that the way we express our ideas is often as important for their persuasiveness as the ideas themselves.