One more Lincoln story that came to mind:

As a young lawyer, Lincoln was pleading a case and asked a witness (appropos of what I do not recall, though perhaps the use of heresay evidence): How many legs does a cow have?

The man grinned at the foolish question and said, Four, of course.

And how many legs would the cow have if we called her tail a leg, continued Lincoln.

With a partonizing sneer, the witness replied, Five.

No, my friend, shed still have four. Just calling her tail a leg doesnt make it a leg.