First and foremost, there’s fertility. Swines are one of those animals whose sexual appetite is proverbial. “To fuck like a pig” is a common expression and any farmer who breeds pigs will probably know a story or two about their prowess. This fits with the sexual nature of the Vanir twins, since Frey has a phallic aspect and is connected to fertility while Freya is known for Her lust. A medieval expression of these notions may be found in Vatnsdæla saga, where Ingimundr, a worshiper of Frey (the name itself is revealing), loses his two pigs only to find them one year later, by which time there were a hundred of them. And a Mediterranean parallel can be found in the cults of Demeter and Ceres, to whom swines were traditionally sacrificed. Finally, another symbolic sense, one that’s related to fertility, is that of abundance: think of the feasts in the village of Asterix and Obelix, the heraldic meaning of a boar’s head, which stands for hospitality and abundant food, and the boar that provides endless meat for the fallen warriors in Valhalla, as told in stanza 18 of the eddic poem Grimnismál.
Boars are also a well-know symbol of fighting valour. Ask any hunter about the dangers of hunting boars and he/she will tell you of their strength and aggressiveness when threatened. It is a fearsome animal whose tusks and brute force can be deadly, which is also in tune with the Vanir Lord and Lady: He, as said, is a capable warrior who will fight vigorously if and only if necessary; She is a goddess of the fallen, whom She shares with Odin. In fact, an alternative name for Ingui’s boar is Sliðrugtanni or Dangerously Sharp Tusks, which is another indication of not only the god’s combative aspect, but also of the animal’s fighting ability. As bucolic as it may seem, a boar is not a peaceful creature, or rather not entirely, and neither is the god to whom it is sacred.
There’s a final and dark symbolic meaning: death! Swines are omnivorous and will eat pretty much anything they can, including dead bodies. That places them on the same level as wolves and ravens, especially when we add the boar’s connection to bellic qualities, and that opens a cascade of meanings: it fits into Freya’s dark side of Lady of the Battlefield, in as much as one of Her names is Sýr or Sow; it also gives sense to the war-helmets crowned with images of boars, which the poem Beowulf says were used for protection, maybe because of the animal’s valour and hence protective ability; and finally, it adds to Frey’s link to the grave, death and renewal, which I mentioned here. There’s a sense of the raven in an apollonian way: Apollo purifies and the ravens stand for that cleansing aspect, since they eat (i.e. eliminate) dead flesh; Ingui’s boar can also consume carrion, but because He’s a fertility deity, the “cleaning” is done by an animal that stands for reproductive abilities (unlike the raven). It is, in other words, representative of the earth’s consumption, the absorption and conversion of dead organic material into fertilizer and hence new life. The great swine as a creative/destructive/creative force.
The boar’s connection to death and renewal leads me to once again wonder if there’s an “Eleusinian” side to Ingui: can that animal be a symbol of a renewed and abundant afterlife? If the Dionysian Dead drink from the god’s cup and are never thirsty, do Ingui devotees eat from the boar’s abundance and never go hungry?