Stefano Mancuso is an Italian plant physiologist at the University of Florence, a founder of the field he calls plant neurobiology, who holds that plants sense their world with all five of our senses and at least fifteen more, and that they are intelligent, if intelligence means the ability to solve problems. Because plants are eaten and cannot run away, he argues, they spread their abilities through the whole body instead of keeping them in a brain. Therapeutic Shamanism welcomes his work and goes further, teaching that plants are conscious beings with their own kind of intelligence, a collective consciousness different from ours and in no way lesser.
Who is Stefano Mancuso? #
He was born in Catanzaro, in southern Italy, in 1965, and is a professor at the University of Florence, where he has led the International Laboratory of Plant Neurobiology. He has published more than three hundred scientific papers and is regarded as a founder of plant neurobiology, the study of how plants take in, pass on and act on information.1 His popular books, translated into many languages, include Brilliant Green (2013, in English 2015), written with the science journalist Alessandra Viola, The Revolutionary Genius of Plants, The Incredible Journey of Plants and The Nation of Plants.12
The writer Michael Pollan, in his foreword to Brilliant Green, tells how Mancuso traced his interest to a story he half-remembered from his teens, which turned out to be the Star Trek episode “Wink of an Eye”: aliens living so much faster than humans that they took the crew for inert matter. That, for Mancuso, is how humans see plants.2
What senses does he say plants have? #
All five of ours, each worked out in a plant’s way, and, in his count, at least fifteen others, among them the ability to sense gravity, electromagnetic fields, humidity and many chemical gradients.3 Light receptors are spread through leaves, shoots, shoot tips and even wood, “as if the whole plant were covered with tiny eyes”.3 Plants smell with their whole body, and the scents they give off work as their words; a plant under stress releases a chemical whose meaning is, in effect, ‘I am not well’. They hear through the ground, not the air: low, bass frequencies help seeds sprout and roots grow, whilst higher ones hold them back. And seedlings can tell their siblings from strangers, putting out fewer competing roots beside their kin.3
A plant that has receptors for something, by his own caution, has not thereby been shown to perceive it, though the receptors may be a good sign that it does.3 And he never lists the fifteen extra senses one by one.
Why does he call plants intelligent? #
Because he defines intelligence broadly. Of the many definitions on offer, he chooses one that fits plants: “Intelligence is the ability to solve problems.”4 Every living thing has to solve problems of food, water, shelter, defence and reproduction, so intelligence, for him, is a property of life itself, and the difference between a human’s and a bacterium’s is one of degree, “only quantitative, not qualitative”.4
What makes plants hard for us to see as intelligent is that they are built on a different plan. An animal has organs, and losing one can kill it. A plant, which may have most of itself eaten and grow back, has no single organ it cannot do without, so it spreads its functions through the whole body; a tree is much more like a colony of bees or ants than an individual animal.5 He takes up Charles Darwin’s suggestion of 1880 that the tip of a root acts like the brain of a simple animal, whilst insisting that plants have no organ that remotely resembles a brain; instead each of a plant’s many root tips works as a small computing centre, and together they may behave like a swarm.5 In one of his liveliest lines, “Their intelligence is distributed!”6
He also argues that the old view of plants as immobile and unfeeling is not a fact about plants but a cultural construct going back to Aristotle, who ranked them a level below animals.7 On that ground he supports the dignity of plants, as the Swiss Federal Ethics Committee on Non-Human Biotechnology declared it in 2008, whilst holding that respecting plants does not mean ceasing to use them, any more than respecting animals has removed them from the food chain.7 See What does animism say about killing and eating?
Is his work accepted by other scientists? #
Partly. Many plant biologists accept the findings on plant senses and signalling but reject the language of intelligence and neurobiology. In 2007 thirty-six of them signed a letter objecting that the name suggests nerves and a brain that plants do not have.8
Even Pollan, in his foreword, notes that the term ‘plant intelligence’ strikes many plant scientists as tendentious.9 Mancuso’s reply is that nobody since Darwin has ever claimed there is a walnut-shaped brain hidden in the root. The real claim is that root tips carry out many of the functions a brain carries out in animals.10 For the wider debate, and the disputed experiments on plant learning, see What does science say about plant intelligence?
How does Mancuso’s work connect with Therapeutic Shamanism? #
Warmly, on several points. Hunter-gatherers did not see plants as less than animals, as things lacking consciousness and awareness, but as conscious beings with their own kind of intelligence, part of the PeoplesThe Peoples. The Animal People, Plant People, Standing People (the Trees) and Stone People: our elder kin, of whom the Human People are the youngest and least wise. A family, not a hierarchy. Read the full answer, with great teaching and healing gifts.11 Some scientists now recognise that plants are conscious too, though in a different way from us.12 Mancuso’s account of plants built so differently from animals, sensing and responding through the whole body, is a scientist’s description of that difference.
His Star Trek story makes the same point as the teaching on slowing down. Plants, free of the restless need to be doing things, live at a much slower pace than animals; humans are like the fast aliens, moving too quickly to notice the sentience of plants, and some scientists studying plant intelligence say we had not slowed down enough to see it. To grok a Plant, a person has to slow right down.13 Pollan puts it that the lives of plants unfold “in what amounts to a much slower dimension of time”.14 See What are Plant People and what gifts do they bring? and What are grokking, dieting and research in working with the Peoples?
Where does Therapeutic Shamanism see things differently? #
In three places. First, in Brilliant Green Mancuso speaks of intelligence, and of plants as sentient in the sense of having senses; nowhere in that book does he call them conscious. Therapeutic Shamanism does. Plant consciousness is collective-awareness, at the far end of a continuum from human self-awareness; humans are so far towards self-awareness that most of us cannot even recognise collective-awareness as consciousness, and understanding it is at the heart of beginning to understand plant sentience.15 The collective Mancuso describes is the single plant as a colony; the collective in Therapeutic Shamanism reaches to the whole species. See What is an Oversoul?
Second, his picture is graded, with human intelligence “obviously much greater” than a bacterium’s.16 Animism has no such scale: humans are the youngest of the Peoples, and that is not about hierarchy but about family.17 See What is the myth of human supremacy?
Third, the knowing itself. Science learns about plants from outside, by measurement. Therapeutic Shamanism also comes to know them from inside, through relationship and the shamanic journey, a way of knowing that neither depends on the science nor competes with it.
