Its purely chemical and much slower than a nervous system. Really just signaling and arguably we dont even know if animals feel/expirience pain like we do either. Kinda begs the question what is actually capable of suffering

You'd be surprised how much we thought the world was magic just a few hundred years ago. In 100 years from now people will look down at us like complete ignorants just like we look down at our ancestors.

Yeah, I think I saw this movie. Snowpiercer.

A worm or a fruit fly has a nervous system. Does it feel pain? How do you quantify it?

It’s not unreasonable to assume that if a nervous system is present and similar pain signals are send, similar suffering is experienced by animals as humans. Simply because suffering is a motivation to take action. There might be a difference in that most animals, like baby’s, wont be able to seperate themselves from their suffering/pain. I am suffering vs suffering is all there is. If thats the case, pain for animals might even be worse then humans. That might be backed up by the fact that most animals are very pain avoidant (makes them really scared), where some humans seek it out, and most of us are able to accept a bit of pain to get something better. (There seems to be some indication that other animals have a sense of self, like dolphins, certain birds, elephants etc) (Also seems that pain for animals, same as with humans, is not felt when they are filled with adrenaline and in fight mode)

How can you be so convinced that plants feel nothing given that we have absolutely 0 understanding of what consciousness is?

How do you suppose one can feel pain with a nervous system? We have no explanation or real understanding of the mechanism that underlies human consciousness, so there's no real reason why it couldn't occur via a mechanism that plants share.

But you would have to redefine pain to ignore the experience aspect. And that would be a completely different phenomenona. Yes it may share the same mechanism, but so what?

Plants are immobile. The only mechanism they have for moving about is relatively slow and lacks agency. They can grow in a particular direction, send out a clone,or use reproduction. A hormonal reaction to external stimuli could trigger that kind of behaviour. But what advantage would there be in having a consciousness? A chicken on the other had can run away. It can hide. It can learn to avoid damaging itself. Pain has an advantage.

> But you would have to redefine pain to ignore the experience aspect

No, it's the opposite. Plants clearly don't have the reactive aspect, but we have no idea whether they have the experience aspect, because we have no idea what causes experience or how it works.

We also don't know that consciousness provides an advantage to animals. We associate consciousness with intelligent response. But it may well be possible to have intelligent response without consciousness (e.g. like computers, although technically we can't be sure that they don't have consciousness either)

An intelligent response without consciousness is different to an intelligent response with consciousness. That is the re-definition.

We can speculate that the full human experience of pain may exist in the absence of a brain. And we can estimate the probability of that being the case in plants. Do you really think that probability is high?

Also, plants can and do react to damage and even touch.