I would like to thank the many readers who took the time to respond to my previous post for The Stone, “If Peas Can Talk, Should We Eat Them?” Among the approximately 350 comments were several who opposed or misread the argument underlying the piece: that plants have a more complex existence than most people believe, and that that fact should move us to reconsider our ethical approach to eating them. I’d like to address some of those misreadings and objections.
Although recent studies in botany are certainly groundbreaking, both Western and non-Western philosophers have been aware of what we may now call “plant subjectivity” for millennia. Most famously, Aristotle postulated the existence of a vegetal soul with its capacities for reproduction growth, and nourishment, as the most basic stratum of life. To Aristotle, all living beings, including animals and humans, are alive by virtue of sharing this rudimentary vitality with plants. Other levels of the psyche — the sensory and the rational — then presuppose the presence of vegetal soul for their proper functioning and actualization.
Contemporary research into plant intelligence, spearheaded by Anthony Trewavas (University of Edinburgh), Stefano Mancuso (University of Florence) and Richard Karban (University of California, Davis), among others, complicates this tripartite division. For example, studies have found evidence of “deliberate behavior” in plants: foraging (note that the botanists themselves use this word usually associated with animal behavior) for nutrients, the roots can drastically change their branching pattern when they detect a resource-rich patch of soil, or they can grow so as to avoid contact with roots of other members of the same species, in order to prevent detrimental competition. Of course, plants are not capable of deliberation or of making decisions in the human sense of the term. But they do engage with their environments and with one another in ways that are incredibly sophisticated, plastic and responsive — in a word, intelligent, though not perhaps conscious.