The Rod of Mercury

The Jack of Spades carries the caduceus which is the wand of Mercury, and he is the left or right bower, he holds more power than the Ace of Spades which represents the mitre of the high priest. As the High Priest outranks the king, - as even in modern England the Archbishop of Canterbury told Edward he must resign - so the aces or oaks outrank the kings. Kings and other Jacks carry swords, spears, or axes, the Jack of Spades is the only card carrying the Caduceus. This wand of Mercury - which was selected by the medical association to be the emblem of doctors of medicine - was a more powerful weapon than the sword - as the pen is mightier than the sword.