Consider: "Ideas are worthless without execution."

Assume it is true. It's an idea, so it refers to itself, and it is only worthwhile with execution. Since it is not executable, then if it is true, it is worthless.

Assume it is false. It is worthless, or only worthwhile inso far as it's falsehood is useful.

So, "Ideas are worthless without execution" is itself worthless or false and useful.

In no (possible) case, is "Ideas are worthless without execution" both true and worthwhile.

I don't need examples. I just need logic.