The inner life of plants awakens the passions of even the most gentle-mannered naturalists. The controversy about plant consciousness and intelligence has raged in scientific circles for more than a century — at least since Charles Darwin discovered in 1880 that the understated flora can not rest.
There is no question that the plants are highly complex. Biologists assume that plants interact with each other, fungi, and animals by releasing chemicals via their roots, branches, and leaves. Plants often send information-supplying seeds, acting as data packets. They also preserve vulnerable members of their species by supplying nutrients to their peers, which suggests a sense of parenthood.
But does any of this qualify as consciousness? The answer to that question seems to depend largely on linguistics, rather than science—how humans choose to define our conceptions of the self and intelligence.
Philosopher Michael Marder, meanwhile, says we’re underestimating plants. The author of Plant Thinking: A Philosophy of Vegetal Life, Marder tells Gizmodo, “Plants are conscious, though in a different way than we, humans, are.” He notes that plants are in tune with their surroundings and make many complex decisions, like when to bloom. Marder concludes, “If consciousness means being ‘with knowledge,’ then plants fit the bill perfectly.”
Marder points out that plant cuttings can survive and grow independently. That suggests that if plants do have a self, it is likely dispersed and unconfined, unlike the human sense of self. It’s notable, too, that many scientists and mystics argue that the human feeling of individuality—of being a self within a particular body—is a necessary illusion.
Acknowledging plant intelligence could put us in an awkward position. Perhaps there is nothing we can eat that isn’t some form of murder, not even salad. Moreover, if we discover plant kinship relations are real, we’ll need to acknowledge that cutting trees down for furniture means splitting up families. More than that, expanding definitions of consciousness and intelligence could mean admitting we’ve been limited in our worldview altogether. What if everything around us is intelligent in its way, and we’re just not smart enough to see it?