Pain is an evolutionary adaptation that indicates animals of danger and forces them to avoid and move away from it. For example if an animal put its hand over fire this would damage their cells and reduce their chances of survival, so our pain receptors activate and we then become instinctively aware that the stimuli should be avoided and is a threat to their survival.
Because the brain is a crucial part of the nervous system and the process of feeling pain, animals that are less intelligent than us humans arguably feel more pain as they need more of an indicator to render something as dangerous. Of course this cant be tested as pain is subjective, however this is something to keep in mind regarding ethical issues like eating animals products or animal testing.
Well unlike animals, plants cant move away or escape from danger, so from an evolutionary stand point it would not make sense for them to feel pain as it does not increase their chances of survival. Instead plants have adapted different features such as the ability to detect sunlight and change their orientation to face it. Also some plants in rainy environments have devolved large leaves to collect the most amount of water. In contrast to feeling pain both of these adaptation are actually useful for the plant to prosper and strive.
This concept was understood by one of the greatest minds Leonardo Da Vinci:
“Though nature has given sensibility to pain to such living organisms as have the power of movement, – in order thereby to preserve the members which in this movement are liable to diminish and be destroyed, – the living organisms which have no power of movement do not have to encounter opposing objects, and plants consequently do not need to have a sensibility to pain, and so it comes about that if you break them they do not feel anguish in their members as do the animals.”[13]
Yes, plants are alive however they do not have a brain, nervous system or pain receptors. They are not sentient(feel pain) they are only intelligent and respond to stimuli just like the phone in your pocket. So would you suggest that your phone feels pain? No of course not there is a distinct difference between intelligence and sentience.
Lastly if you just think what would you rather "kill" an animal like a dog or a carrot, the majority of people would definitely rather a kill a carrot. Because instinctively we know that they do not feel pain as they do not have the attribute of an organism that feels pain.
Hopefully this has educated you on this topic and cleared up any misconceptions or questions you have had. I will be posting more content like this in the future so if you found this helpful upvote and follow :)
