“The Spiritual Life of Plants: Can We Truly Understand Their Needs and Reactions?”

“A tree has no eyes,” said Daniel Dennett, “because it can’t jump away from the approaching car anyway.” Every organism has a sensory apparatus with which it manages. The buzzard sees the mouse from a height of thirty meters. Because they can’t run off, plants don’t have a sensory device that you need for fast movements.

Yet they can react quickly. Look at the giraffe and the acacia. When a giraffe starts to nibble on an acacia, the damaged leaves release a substance that warns the acacias that are winded down so that they have time to make their leaves a bit more bitter. As a result, when the giraffe slides up a tree, it encounters dirty leaves and seeks refuge elsewhere. However, the giraffe has been trotting along in this circus for many years and that is why there are giraffes who, after nibbling on an acacia, simply skip the next two and only continue to eat at tree four. Isn’t it great?

We immediately assume that the giraffe can be in pain. But is there spiritual life in the acacia that gives that speck of dust to the wind? And also in the acacia that makes her leaves bitter? Is the eaten acacia scared? Are her sisters getting stressed and is that reflected in those bitter leaves?

In NRC of April 16, Eva Meijer and Yvonne Faber write about the spiritual life of plants under the title: ‘Take plants morally seriously’. They cite a study that found that plants make ultrasonic sounds, too high for humans to hear. ‘Plants that experience stress appear to make more noise than plants that don’t, and there are differences between species: tomato plants, tobacco plants, maize, cacti and grapes all have their own alarm calls.’

This is something to think about for a while. Your dog has an alarm call that you will hear immediately if you accidentally step on her tail. The effect is that from now on you will be more careful when you walk around her. But why should tomato plants, after an evolution of many millions of years, come to produce ultrasonic sounds that no one hears? It’s like they’re holding up a sign that reads “AU!” in the hope that the deer will not nibble on their bodies, even though those animals cannot read.

The authors do not say where and how the various plants produce ultrasonic sound. Their goal is clear, they advocate a respectful treatment of plants. And they believe that this cannot be the case if we do not listen to the needs of plants. Plants receive information from their environment through their roots. ‘Despite the fact that a plant does not have a central brain, that information is passed on from root to leaf with similar ‘neurological’ processes as in animals.’

The quotation marks around ‘neurological’ speak volumes as far as I’m concerned. You can find similar ‘neurological’ processes in every computer, without suspecting a ghost in it. They definitively undermine their theme with this statement: ‘The fact that plants make noise when stressed is of course also a very telling example: if we heard it, we might act very differently’. Nice. But we don’t hear it! Nor do we see any sign in the behavior of herbivorous animals that they do hear. To which you should immediately add that those herbivores would continue to eat if the plant said ‘ouch!’ in any language. would call. The buzzard hears the mouse’s desperate squeak very well, but there is no room in the buzzard mind for the question, “Oh God, what am I doing to this little mouse?”

The biologist says that a stress signal (lamb bleats, mom comes to the rescue) is only developed if it is functional, that is, if it is received. Ultrasonic sound from plants falls nowhere or falls on deaf ears. Wittgenstein said of the presumption of pain or stress in creatures around us, that an inner experience needs an outer characteristic. If these ultrasonic sounds are an external characteristic, it is still a guess as to the experience that goes with it. stress? That is an unfounded projection.