The Man Who Has Learned That Three Plus One Are Four Doesn't Have To Go Through A Proof Of That Assertion With Coins, Or Dice, Or Chess Pieces, Or Pencils. He Knows It, And That's That. He Cannot Conceive A Different Sum. There Are Mathematicians Who Say That Three Plus One Is A Tautology For Four, A Different Way Of Saying "four" ... If Three Plus One Can Be Two, Or Fourteen, Then Reason Is Madness.