Here’s a thought-provoking article from Slate.com. We couldn’t help but notice the correction at the bottom of the story: “The caption for this story originally stated that Arwen and Aragorn are half-elf and half-human. Their lineage is apparently much more complicated than that.” Knowing fellow Tolkien fans, we imagine they received a comment or two (or twenty) to set them straight!
Are hobbits human and just really short? Or are they some entirely other species, like a gold-hoarding dragon? In high-school biology class they teach you to define species in terms of interbreeding. A horse is something that can make nonsterile babies with other horses; it may mate with a donkey, but since their offspring are sterile mules, horses and donkeys count as separate species. By that standard, the most relevant J.R.R. Tolkien passage comes from Appendix A of the Return of the King:
There were three unions of the Eldar and the Edain: Lúthien and Beren; Idril and Tuor; Arwen and Aragorn. By the last the long-sundered branches of the Half-elven were reunited and their line was restored.
It helps to recall here that Eldar is another word for elf and Edain is another word for human. Tolkien is saying here that there were two human-elf pairings in the backstory to the Lord of the Rings. One between Lúthien and Beren and another between Idril and Tuor. Both Arwen and Aragorn are descendants of one of these pairings. So when they get together in the course of the series, they reunite the half-elven lines. [Read More]