In the ending think about "The bite of the apple". Seligman was a virgin and a pure person, that's why he tried to rape Joe without any bad intention. He should have gotten a bite too in the allegorical way as everyone does to distinguish bad from good. He acted like a moron because his whole life he was reading books instead of living and learning from his experience. Books without experience are just food for thought.
Review of Nymphomaniac: Vol. II
