I was looking to update my picture of Bosch's "Prodigal Son" picture (the earlier link disappeared) when I ran across this very interesting article (
http://www.fictionwise.com/knight/boschtwentytwo.html) by Damon Knight which shows both of Bosch's treatments of this theme.
I still think the round one is the greatest fool "card" I've ever seen.
Knight says it's a mistake to identify the painting with the Prodigal Son, that its real name is "The Wayfarer." That'll work.
But I still think of that figure who's looking one way and going the other as the Prodigal, whom the Book of Luke (KJV) says "tooke his iourney into a farre countrey, and there wasted his substance with riotous living."
He really is a fool, having blown all his money on wine and women, and in pretty desperate straits -- skinny, hungry, not a friend to be found, even the dog hurries him along. He's got nothing, and is so desperate "he would faine haue filled his belly with the huskes that the swine did eate." His spoon, prominently at the ready, symbolizes his hunger.
The swine are (barely) visible in front of the run-down tavern where this fool met his ruin. It's partly unroofed; there's a sleazy-looking couple making out in the doorway and a guy pissing in the shadows of the east wall. Hell of a glamorous place to lose your money.
Best of all, Damon Knight makes the (I think) obvious Wayfarer -- Fool card connection. Scroll down the bottom of the page where he says "There is a strong resemblance between The Vagabond and The Fool in the Waite-Smith Tarot deck, and an even stronger one in the Marseille deck (late fifteenth century), but this resemblance cannot be traced back any further; the Visconti-Sforza decks do not have it. It seems less likely that Bosch was inspired by an ur-Tarot, now lost, than that later versions of the Fool were based on Bosch's painting. The number of the Fool card, 0, also suggests that it was a late addition.
"The Tarot suits of wands, cups, swords, and coins can all be found in Bosch's paintings, and there are certain resemblances in The Tower, Judgment, and a few other cards, but there is no good evidence that Bosch's work arose from these."
I'm not sure about Knight's conjecture. Bosch was born in 1450, the approximate year of the Visconti-Sforza, and died in 1516, still very early in the history of tarot. Still, the Netherlands was an import-export economy, whose cities got all manner of exotic goods from around the world.
Or maybe it's the case that the homeless, destitute, and possibly unhinged Vagabond was an archetypical figure in medieval and renaissance literature and lore.