The exact means by which he divines futures is not known, but may be an applied variation on the theme of haruspicy, which is the age-old art of reading the future in spilt entrails. Indeed, Wikipedia notes that another word for "haruspicy" is... extispicy. Evidently Jeremy is the sort of thoughtful pork butcher who one day may have had a revelation of some sort whilst butchering a porcine corpse, and realised becoming a haruspex represented a useful opportunity to diversify. Even if the only reliable interpretations of spilt porcine offal are
- That the soul of the pig has departed to meet its maker, and
- The future involves quite a lot of tasty nutritious meals from named meat,
then Jeremy evidently has a thriving business and this proves that in Ankh-Morpork, there are people prepared to try anything.
Interestingly, his advertising material reproduced in The Compleat Ankh-Morpork shows a profile of the pig with the major prophetic areas illustrated and named - "The pillars of mordant mercies", "Exemplum Gratis", etc. One area, running along the spine, is called The Rings of Bissonomy. Hmmm.
UNRAVEL THE MYSTERIES OF YOUR FUTURE IN THE OFFAL OF FATE! (WITH OR WITHOUT THE ONIONS OF DESTINY)