Define personhood

It's not easy, but we have to draw the line somewhere:

Given that personhood confers such power and security, it’s no wonder that advocates seek to extend the label to the corporations, pets, primates, and fertilized eggs we want to shelter. But since America hasn’t always recognized the rights of certain classes of genuine human beings, it’s understandable that many would be alarmed by the extension of personhood to corporations, poodles, or embryos. These attempts can seem outright demeaning, as in the case of a recent suggestion by PETA that the slavery-abolishing 13th amendment should apply to killer whales at SeaWorld.

For a less legal, and more philosophical view, consult the following post.