The Halfway Fallacy

1.0 The Halfway Fallacy

Some time ago, Bentham’s Bulldog (BB) presented the following argument in this blog post:

Suppose we’re about to discover whether moral realism is true. Someone offers you a bet. If it’s true they get a dollar, if it’s false you get 10,000 dollars. Should you take the bet?

No. Here’s why. If moral realism is true, then winning the bet actually makes you better off. You have a genuine reason to not [sic] the bet — you’d just lose a dollar. But if anti-realism is true, you are not made better off, nothing matters, and taking the bet doesn’t make you better off. You only have genuine reason in one case.

This argument is an excellent demonstration of what I call the halfway fallacy. I use the term “fallacy” here loosely, since it’s more of a presumption others are free to contest, a kind of philosophical oversight.

The halfway fallacy occurs when one argues that a particular position contrary to their own has one or more flaws or undesirable characteristics, but those f…