Wednesday, March 26, 2014

A valid argument for a flat earth

1. If Charles Johnson (former head of the Flat Earth Society) says the earth is flat, then the earth is flat.

2. Charles Johnson says that the earth is flat.

3. Therefore, the earth is flat.

Validity, by itself, doesn't do a whole lot.

4 comments:

Dave Duffy said...

Victor Reppert, a “Philosopher” and “Christian” stated this was a valid argument for a flat earth.

1. If Charles Johnson (former head of the Flat Earth Society) says the earth is flat, then the earth is flat.

2. Charles Johnson says that the earth is flat.

3. Therefore, the earth is flat.

A single quote, by itself, doesn't do a whole lot.

Benjamin Thompson said...

yes that is true, but oddly enough an invalid argument does far less.

IlĂ­on said...

Logical validity cannot establish truth, for an act of reasoning may be logical yet false. On the other hand, no act of reasoning can be illogical and true.

im-skeptical said...

Of course, this example is precisely equivalent to Lewis' AFR:


1. No belief is rationally inferred if it can be fully explained in terms of nonrational causes.

2. If naturalism is true, then all beliefs can be fully explained in terms of nonrational causes.

3. Therefore, if naturalism is true, then no belief is rationally inferred (from 1 and 2).

4. We have good reason to accept naturalism only if it can be rationally inferred from good evidence.

5. Therefore, there is not, and cannot be, good reason to accept naturalism.

Statement 1 of this argument is no more true than "1. If Charles Johnson says the earth is flat, then the earth is flat." So Lewis' AFR, while it may be a valid logical argument is a failed argument. (Unless, of course, premise 1 can be shown to be true.)