If you haven’t been following the slow growth of acceptance of panpsychism (everything is conscious) in the sciences, you might be surprised to learn that the idea that plants have minds is a serious — though currently contested — claim in biology:

In a 2021 article in the journal Protoplasma, critics called it ‘regrettable’ that ‘claims [by scientists] that plants have conscious experiences’ are ‘finding their way into respectable scientific journals – even top-tier journals’, which might ‘generate mistaken ideas about the plant sciences in young, aspiring plant biologists’. These claims are ‘misleading and have the potential to misdirect funding and governmental policy decisions.’ One wonders what harm they think granting plants minds might cause – and if it is somehow more severe than the reverse.

Rachael Petersen, “Do plants have minds?,” Aeon, June 11, 2024

The author of the essay at Aeon, Rachael Petersen, leads the Thinking with Plants and Fungi Initiative at the Center for the Study of World Religions at Harvard. As it happens, some scientists seem to push the boundaries on fungi intelligence too.

What would surely puzzle some observers is the considerable current effort — at the same time — to portray human intelligence as some sort of illusion. Right now, illusion thinking rules because physicalism (everything is physical) is the reigning philosophy of science. But if panpsychism continues to gain ground, the human mind can at last be acknowledged to exist — along with the cabbage mind, the mushroom mind, and possibly the electron mind.

But first, what about plant mind?

Petersen devotes most of her essay to the life and thought of 19th-century German physicist and philosopher Gustav Fechner (1801–1887), who eventually found personal peace in the idea of plant minds. In fact, he seems to have found it hard to distinguish between plant and human minds:

In [his 1848 book] Nanna (named after the Norse goddess of flowers), Fechner argues that plants are conscious beings with feelings and desires. They delight in the sun as we might delight in a wholesome meal. The world strikes plants with pleasure, pain, and even meaning.

Nanna asserts that we can only ever infer the existence of inner experience through outward physical expressions. And although we cannot fully know nature from within – eg, we can never get inside the mind of a plant – we can get close through comparison. We do this all the time, Fechner says. We assume some shared inner experience when we gaze into the eyes of a lover, parent, friend or foe: ‘My conclusion that you, my friend, have a mind is founded at last upon the fact that your outward appearance, your speech, and your behaviour are analogous to mine.’ If you are like me, you must have a soul like me.

Petersen, “Do plants have minds?”

Lost in the undergrowth is the fact that we reasonably believe that other human beings have inner lives like our own because they are fellow humans. We have no similar reason to believe that of trees or seaweed.

In Fechner’s world, plants might reason too:

Fechner imagines that plants could apply their own soul criteria to humans and find us lacking. Plants may assume, based on their own experience, that the soul is evidenced by a capacity to self-generate and self-adorn, to create one’s body leaf by leaf. But humans must ‘leave our body as it is’ and don external garments. In addition, the plant is sessile; we run about. ‘The oak,’ he writes, ‘could easily turn our arguments against her soul back against ours.’ To plants, we must look very soulless.

Petersen, “Do plants have minds?”

Petersen generally sympathizes with Fechner’s approach, hinting that doubters suffer from what he called “soul-blindness.” She sees plant mind as a trend in science: “Several scientists who support the cognitive capacity of plants also hold out the possibility that they are sentient – what Fechner called ensouled (beseelt).”

Some qualifications would come in handy here

As we’ve noted here at Mind Matters News, plants have nervous systems and communicate extensively. But so do machines, if programmed to do so. We can’t assume that either plants or machines are sentient — that they have sensations or emotions — simply because they communicate. Unless, of course, we assume that everything has a soul. And, it turns out, that is just what Fechner did come to think. In a later book,

… Fechner gives Nanna a cosmic upgrade, extending his analogical reasoning to celestial bodies. Couldn’t Earth be said to behave, in some ways, like the human body? Could it also have a soul? All of creation harboured an interiority, a rich sensuous life, a kind of freedom. And humans comprise, in part, this terrestrial consciousness. We rise upon the planet as wavelets rise upon the ocean. We grow out of her soil as leaves grow from a tree. We are the sense organs of Earth’s soul: when one of us dies, ‘it is as if an eye of the world were closed,’ as William James said in a lecture concerning Fechner’s thought.

Petersen, “Do plants have minds?”

It may be that panpsychism logically ends up embracing conscious planets and electrons. But that’s for philosophers to debate. Here we are looking at trend lines. Petersen asks above, “One wonders what harm they think granting plants minds might cause – and if it is somehow more severe than the reverse.” Well, one harm is that there are bound to be people who begin thinking that salad is murder.

We’re just beginning to see the challenges panpsychism will present.