I think of pain as A signal, not the only one. So, to correct my assertion, i would say that we're not alive with the set of signals we have now. Then i would consider that alive means that we experience the same signals. BUT that means that a blind person is not alive. My initial statement is not accurate now.

> If we're not in pain, we're not alive.

That's a silly assertion. Pain isn't a hallmark of life--physical, mental, or otherwise. There's no 'merit' to it.

There are plenty of organisms without pain receptors that are definitely alive.

Pain doesn't correlate with how alive we are or the worth of our lives. Chronic pain sufferers would certainly rather not have pain.

I'm sure chronic pain sufferers will feel much better knowing that.

Hell no! Pain is one of the biggest causes of human suffering. Having said that, until something better is "invented" pain is absolutely necessary, all those people who cannot feel or have a high tolerance to pain are always hurting themselves involuntarily. You lose your feedback signal.