You might’ve been here before: you’re trying to explain to your deluded Bay Area friends that Colin Kaepernick is not – and will never be – an elite quarterback.

“He throws when he should run. He runs when he should throw. He’s just plain dumb…”

Your friends are aghast, and they pull their trump card: Kaepernick had a 4.0 GPA in college, and scored phenomenally high on the Wonderlic Cognitive Ability Test before the NFL draft. Thus, they think they’ve established that you’re unequivocally wrong. And of course, they proclaim, that means they are right.

Nah.

What we have here is a classic example of an Exclusivity Fallacy. This may sound a lot like a False Dichotomy, and indeed the two are very similar. Both names are relatively self-explanatory. An Exclusivity Fallacy unjustifiably excludes other possibilities – in this example, that Kaepernick’s quarterbacking lies somewhere between bad and elite, or perhaps that he’s not a quarterback at all but rather a projection of our collective imagination (unlikely, but possible). A False Dichotomy, however, fallaciously suggests that there are only two possibilities; either you are right or I am right.

Note that the two differ slightly in that a False Dichotomy means you specifically present two (di) and only two possibilities, whereas an Exclusivity Fallacy could present any number of possibilities, so long as at least one is excluded.

Here, your 49er fan buddies are engaging in both an Exclusivity Fallacy and a False Dichotomy by deducing their rightness from your wrongness, and ignoring the third possibility that neither of you are correct, and that Kaepernick is a somewhat strong QB, but neither truly terrible nor truly exceptional.

One of the most famous examples of an Exclusivity Fallacy can be found (surprise, surprise) in George W. Bush’s speech to Congress declaring that “either you are with us, or you are with the terrorists.” As with the above, anything outside the rigid binary is excluded; there are only two possibilities. That’s fine for rhetoric, but it’s logically laughable.

The moral of the story? Don’t fall for the Exclusivity Fallacy, don’t listen to George W. Bush, and don’t be a Niners fan.