Reply #19: A little background from the Middle Ages

[jobycom]

Medieval culture considered fish more of a fruit than an animal (different scientific classification methods, obviously). The French still call seafood "fruit of the sea." Christians weren't supposed to eat meat during Lent, and that eventually evolved into only on Fridays during Lent, but since fish weren't meat, they could still eat fish. That part of the tradition continued.

So maybe that's your friend's philosophy.

There's no controlling legal authority, so he can eat what he wants, but as for me, fish is an animal and I don't eat them. Then again, I never liked fish much, anyway.