Last week, I was invited to the Yom Ha-Atzma'ut celebrations at the home of the President of Israel. It is a long ceremony, involving awards to the 120 most outstanding soldiers, songs by the Prime Minister and President (!), and lunch. For various reasons, I was not able to go.
Which was just as well. It turns out that the caterer discovered, the day before Yom Ha'Atzma'ut, that the meat had all spoiled. Shockingly, he decided to replace it with meat from a supplier in Abu Ghosh - which was, of course, entirely treife. Somehow slipping it past the mashgiach, the caterer thought he had gotten away with it. But it transpired that he had been caught on the security cameras in Abu Ghosh. Unfortunately, this was only after the meat had been eaten by the guests.
And so it's just as well that I didn't attend the event. Because if I would have gone, then I would have inadvertently eaten treife, and... what?
As Professor Menachem Kellner explains, in Maimonides' Confrontation With Mysticism, the consequences of inadvertently eating treife are subject to a dispute between Rambam (Maimonides) and Ramban (Nachmanides).
According to Nachmanides (and probably most other rabbinic authorities), non-kosher food inherently houses spiritual harm. If one had some kind of metaphysical measuring device like those of the Ghostbusters, one could take a measurement of it. Like poisonous food, it will cause harm even if one eats it entirely inadvertently.
According to Maimonides, on the other hand, the laws of kashrus are institutional rather than relating to some kind of metaphysical reality. There are various reasons why we must not eat non-kosher food, but it has nothing to do with anything metaphysical inherent to the food itself. Consequently, if one inadvertently and unknowingly eats non-kosher food, one's soul has not been harmed.
Personally, the thought of eating treife food, even inadvertently, gives me the heeby-jeebies. I guess I'm not so much of a rationalist, after all.