If you look back over the past 7 pages you will find that I have been involved in a discussion on the sentience of plants and not an ideological war on the righteousness of Buddhism and the Buddhist view. This only occured after you threw out the "heresy watch" accusation. So can we put it to rest now and get on with the point at hand please? ie "Are plants sentient?"
There is nothing intrinsically non-Buddhist about the idea of plant sentience. However the scholastic tradition made it clear that it was uncomfortable with the idea precisely for the same reason you are: what about the karma of eating and killing plants? Thus, the resulting judgment that plants are insentient is truly just a utilitarian claim meant to ease the consciousness of Buddhist scholastics. Because it is certain that common people in India continued to regard plants as sentient, and do so up to the present.
Since you have a background in biology, Matthew Hall suggests that the problem in adressing plant sentience is a function of entrenched zoocentrism in cognitive modeling which begins with Aristotle. When the question gets brought up, the immediate response is "where is the nervous system, where is the brain, etc." It does not occur to people to ask "If plants are sentient, how might plant neurobiology differ from zoomorphic neurobiology?" In particular, in Hall's book on page 147 he discusses the issues of plant brains.
The conceptual problem, as I see it, is that in Buddhism we have substituted "consciousness" for a soul, or a living being (jiva). But Buddhism no more moves away from a decentralized notion of sentience that does Aristotle. Truthfully, there really is not much difference between the idea of a transmigrating consciousness as the irreducible fact of a sentient being and a soul (despite the chorus of protests this will raise). A transmigrating consciousness transmigrates precisely because of the delusion of selfhood. We take rebirth because we are deluded about I-ness. The only difference between the early Buddhist anatman and the Hindu atman is what is taken as identity. The Hindus understand all persons and phenomena as lacking identity, but suppose that underneath all these illusory appearances, there is a permanent sat-cit-ananda, whose definition is very much like the Mahāyāna definition of tathagatagarbha i.e. permanent, self, blissful, and pure.
The issue, as I see it, is that the substance dualism implicit in the way scholastic Buddhists treat namarūpa make a systems theory of consciousness impossible. This is not an issue in Dzogchen (and to a lesser extent, in Vajrayāna), because consciousness itself is a product of systems interactions i.e. the interactions of the five elements in the body and so on.
What I propose is that the language of plant devas in Buddhist literature is used as a device to ameliorate karmic responsibility for using plants as food. Certainly, in animist traditions where plant spirits are considered, it is not like that. We consult with the spirit of the plant before using it, just as we consult with the spirits of animals we hunt. When we kill a plant, we do not necessarily kill its spirit, just as when we hunt we do not necessarily kill the spirit of the animal we are hunting. This model is still grounded in a naive substance dualism, but it has the benefit of making us recognize that all our actions of eating involve taking life and the life of one living being is not held to be more important than that of another.
Of course in the East Asian Traditions of Buddhism, plant sentience is also accepted in some quarters. The Shingon views of Kukai are very close to my understanding predicated on Dzogchen teachings:
If plants and trees are devoid of Buddhahood,
Waves would then be without humidity.
As people may or may not know, I am comitted to the principles of deep ecology/biocentrism, and the denial of plant sentience not in keeping with those principles. If we deny plant sentience, as we do merely on the basis of zoomorphic orthodoxy, we deny the intrinsic value of the great preponderance of biomass on our world and reduce it, in bibical terms, as something merely for our use, biological automata, without sense, without feeling, without intelligence. For many centuries, we regarded animals as mere automata too. Now we understand better. In time, I am certain, we will understand this kind of thinking is a mistake when we consider anything that lives.
Very interesting, thanks for your thoughts. I have had some of the same questions and reservations about the Buddhist denial of plant sentience. As of yet, I am undecided either way, but I think it is certainly something to contemplate. As Greg K mentions, there are fruitarian ways to avoid taking the lives of plants and still eat a healthy meal. I believe this was Gandhi's conduct towards the end of his life. Probably, if one was really concerned one could make use of ethically (non-harm) produced dairy products (I met some old lady goat caretakers at the West Hollywood Farmer's Market in LA who treat their goat as pets until they die of natural causes, never selling for slaughter).. and fruit and nuts and manage to avoid the outright destruction of any living organisms. As to the larger question of if everybody on the planet could eat like this sustainably, that doesn't really matter because hardly anyone proportionately (to be realistic) would probably be inspired to.
I think I mentioned this on this forum already in the last year or two- but I started thinking about this again with more fervor after reading this really interesting book which I highly recommend... it is an easy and entertaining read:
Anthropologist Jeremy Narby has altered how we understand the shamanic cultures and traditions that have undergone a worldwide revival in recent years. Now, in one of his most extraordinary journeys, Narby travels around the globe-from the Amazon basin to the Far East-to probe what traditional healers and pioneering researchers perceive about the intelligence present in all forms of life.
Intelligence in Nature offers overwhelming illustrative evidence that independent intelligence is not unique to humanity. Indeed, bacteria, plants, animals, and other forms of nonhuman life display an uncanny proclivity for self-deterministic decisions, patterns, and actions. The Japanese possess a word for this universal knowing: chi-sei. For the first time, Narby presents an in-depth anthropological study of this concept in the West. He not only uncovers a mysterious thread of intelligent behavior within the natural world but also probes the question of what humanity can learn from nature's economy and knowingness in its own search for a saner and more sustainable way of life.