Much has been made by commentators concerning the knives shown in the Garden of Earthly Delights. These have what appears to be either the letter 'M' or 'B' according whether one reads them as upright or on their side.
Bosing in his Hieronymous Bosch: Between Heaven and Hell suggests that it "...likely refers to 'Mundus' (World), or possibly Antichrist, whose name, according to some medieval prophecies, would begin with this letter."
There is a more mundane explanation for this knife. In an excellent article on the "Everyday Objects in the Paintings of Hieronymus Bosch" by Hans Janssen, Olaf Goubitz and Jaap Kottman contained in the catalogue Hieronymus Bosch: New Insights into his Life and Work, issued by the Museum Boijman van Beuningen in Rotterdam, the authors uncovered a table knife found in an archaeological excavation 1995-6 in 's-Hertogensbosch. This is dated to the 15th century and has the same shape and mark used by Bosch. Here Bosch was obviously copying a knife from a cutler in his home town. It could even have been from his own kitchen! So enough of absurd theories. The painter was just using a ordinary familiar object. The symbol 'M' or 'B' has no great significance.
