Sentient beings [有情]— all inhabitants of the three realms of samsara who possess a mind and transmigrate within the six classes of beings. Animate things, such as plants, which do not have a mind, are not ‘sentient’.
Insentient beings [非有情]: Those beings or objects that have no emotions or consciousness, such as trees and stones. The term is contrasted with sentient beings, those forms of life that possess senses, emotions, or consciousness. Buddhism classifies all existences into two categories: sentient and insentient.
Do plants feel pain? Short answer: no.
Plants have no brain or central nervous system, which means they can’t feel anything.
Humans and animals perceive pain through sensory nerve cells. These are the same type of cells that transmit information from our senses, allowing us to smell, see, hear, taste, and touch. These cells are part of what’s called the peripheral nervous system, which includes all the body’s nerves except those in the spinal cord and brain.
Peripheral nerve cells form a network that carries messages from the skin, muscles, and organs to the spinal cord and brain. The brain responds by sending back messages to the pain site that promote the healing process.
So what does all this have to do with plants? Well, biologists know that neural systems like ours and those of other animals (yes, fish included) are one way to process information—but not the only way. Even though plants don’t have nervous systems, they can respond to stimuli. For example, when an aphid attacks a leaf, this sends an electrical signal that goes from leaf to leaf to tell the plant to start protecting itself. But it’s important to note that responding to damage does not mean the plant is in pain.
Unlike us and other animals, plants do not have nociceptors, the specific types of receptors that are programmed to respond to pain. They also, of course, don’t have brains, so they lack the machinery necessary to turn those stimuli into an actual experience. This is why plants are incapable of feeling pain.
But you know who does feel pain? Cows, pigs, chickens, turkeys, fish, lobsters, and all the other living, breathing, feeling animals humans eat. That’s right, humans and many other animals—especially mammals and other vertebrates—all developed similar central nervous system features before we went down different evolutionary paths. This means that not only do animals feel pain, but all farmed animals killed for food likely feel it in similar ways as we do.
So lets go Veg!