I have no evidence that a lobster has consciousness, and it's consciousness (particularly intelligent consciousness, like yours and mine) that, to my very crude ethics, grants "personhood". With personhood comes the right to live and my thinking that it's immoral or some great loss to the Universe to kill you. That is why I think I can eat (and cause untold suffering) to lobsters with impunity for my benefit. :o (Not, to massage your image of me, that I would enjoy harming lobsters; I'd sooner keep one as a pet or release it if it materialized in my kitchen. I don't even like killing spiders or cockroaches, and I don't even eat those! BUT. If other people kill lobsters, I don't consider it immoral, and I'd gladly eat them served to me. But not the cockroaches or spiders.) Pain is bad, but it's bad to conscious beings. A computer can be programmed to react to keystrokes much the same as a creature "with no lights on" can be programmed to react to damaging stimuli, but that reaction brooks no rational response from me. It brooks emotional responses, but acting on reasonless emotion is silly.

Even if you accept my position, you could argue that maybe lobsters do have consciousness. Maybe they're even way more intelligent than we think they are. That'd be a problem. But, being scientific, you have to operate on what you have evidence for, not on what you don't. For the same reason, I don't think abortion is human murder (unless it's late term, after the brain's been thoroughly developed).

Another problem, of course, is where you draw the line. Lobsters aren't intelligent enough for personhood. What about dogs? What about chimps? What about severely mentally handicapped humans? Do you draw the line at doing calculus? (Because then you exclude a lot of normal humans!) That's the problem with fascism. :B I need to rethink my ways. But it's too difficult, and meat is calorically-dense and tasty!