A Big Day for Aristotelians

A plant 'cyborg' has proven to have the capacity to move itself around to seek better light. We all know that plants can detect light, and can engage in some limited movement of their leaves in order to maximize exposure. Scientists have figured out how to translate that into an ability to let the whole plant move itself, determining where it should sit.
The idea is reasonably simple—place sensors that listen to the electrical signals generated by a plant and then convert those signals to commands carried out by the motorized wheels. The result is a plant that can respond to changes in light direction by moving itself closer to the source.
If you are an Aristotelian thinker, this is really an interesting development. Aristotle argues (in De Anima) that the human soul has three parts, the rational, the motive (or animal), and the nutrative (or plant-like). Humans, plants, and animals contain the capacity to take nutrition from the world and put it into our own order: to rebuild our cells, say, with proteins taken from outside us. All of us do that, and it is the distinction between living things and things like rocks that are not alive.

The difference between plants and animals, he thought, was just this capacity to move one's self in order to obtain food. The motive soul was a higher level of soul because it required an ability to distinguish things distant from yourself, rather than simply to absorb things that you came into contact with accidentally. Hans Jonas, in The Phenomenon of Life, argues that this capacity requires a self-conscious mind: a hawk must be able to distinguish that it is different from the rabbit. That isn't necessarily clear, though; there needs to be some sort of process by which the hawk finds the rabbit's presence actionable, but it might not be a conscious process. Still, it makes sense to say it is: certainly, in us, we recognize ourselves as different from the hunted animal. There is no special reason to assume it is otherwise for the hawk, there is just no proof that the hawk experiences consciousness.

(Although, speaking of birds, I think it's at least suggestive that crows not only display advanced problem solving in spite of having brains that contain none of the structures we think humans use for it, they also seem to be able to recognize people who have been mean and to communicate that to others in their murder. But we don't know what their experiences are like, or even if they 'have experiences' at all.)

So anyway, it turns out that plants have the ability to process the information they would need to move around; they just don't, naturally, have the capability to move around. For Aristotle, the soul is the perfection of the thing according to its own nature. Wouldn't the plant be more perfect if it could move, just as an animal would be more perfect if it could reason (as, it seems, crows can)?

If the answer is yes, then we come to another Aristotelian dictum, this one from the Physics: it is the role of art to perfect nature. That is to say that the human soul, which is rational in its highest part, can see where the natural has failed to actualize all of its potential. We can, through art, improve nature by bringing it more fully to its complete perfection. The art of medicine is essentially this, or has been up until now: the eye should see, and see well, but does not, and so the doctor works to try to restore or perfect the sight.

So the question to ask is this: are we perfecting the plants' nature, and if so, does that mean that they really do have an animal (motive) soul that has only existed so far in potency? If so, do they have rational souls in potency as well? We have more reason than Aristotle had to think that animals can reason, at least some of them. Perhaps all animals have rational souls that haven't been fully actualized; perhaps, with art, they could be. Plants as well.

That leads to another ancient view, more Plato's than Aristotle's.


Tom said...

How have Aristotelians dealt with the idea of other animals being rational? Wasn't the rational animal the classic definition of human?

Grim said...

It was the Scholastic definition of humanity, yes, although it draws on both Aristotle and the Neoplatonists. I've sketched one way Aristotelians could deal with it above: by accepting that rationality exists as a potential (and 'potentiality is first actuality' for Aristotelians). Until now humans have fully actualized the potential (or 'more fully'); other animals seem to have partly actualized it.

Other Aristotelians have gone another way, by abandoning the idea that 'rational animal' is the right way to talk about it. Following Hegel's distinctions, I believe, they've begun to talk about humans as 'symbolizing animals.' Hegel talks about the ability to make signs and, significantly differently, symbols as a higher sort of consciousness. There are plenty of animals who make signs, but so far we may be the only ones who make symbols.

But that might fall too; I'm not convinced it won't. I think the Neoplatonists are ultimately going to win out, and panpsychism will turn out to be true. Of course, I could be wrong.

Roy Lofquist said...

Young sunflowers turn to follow the sun. Not exactly mobility, true. The kicker is that they turn to the east before dawn.

"In a newly-published article in Science, the researchers say the young plant's sun-tracking (also called heliotropism) can be explained by circadian rhythms – the behavioral changes tied to an internal clock that humans also have, which follow a roughly 24 hour cycle."


As usual, when faced with anomalies that challenge the catechism, the "scientists" make up some long words that are actually "mumble, mumble". It is unclear whether the sunflowers use Timex or Seiko.

Texan99 said...


Tom said...

Interesting, Grim.

The word “panpsychism” literally means that everything has a mind. However, in contemporary debates it is generally understood as the view that mentality is fundamental and ubiquitous in the natural world. Thus, in conjunction with the widely held assumption (which will be reconsidered below) that fundamental things exist only at the micro-level, panpsychism entails that at least some kinds of micro-level entities have mentality, and that instances of those kinds are found in all things throughout the material universe. So whilst the panpsychist holds that mentality is distributed throughout the natural world—in the sense that all material objects have parts with mental properties—she needn’t hold that literally everything has a mind, e.g., she needn’t hold that a rock has mental properties (just that the rock’s fundamental parts do).

I am not sure what it would mean for something without a mind to have mental properties. How could we know whether the fundamental parts of a rock have mental properties? Somehow, this seems to fundamentally alter the meaning of the word "mental" and the ideas of "mind" and "consciousness."

At first, when I thought we were just talking about living things like plants and animals, panpsychism seemed like something I could easily accept, but when it became clear we were talking about electrons or quarks having mental properties, my categories failed.

Tom said...

I guess this could be a new form of the old idealism where all existence is maintained by the attention of God; if so, then mentality / consciousness might be ubiquitous because all existence is maintained by that conscious attention ...

But it seems to do so w/o an appeal to deity, and instead of being maintained by something external, things are instead constituted of parts with mental qualities.

Grim said...

A very easy way to do it is the Aristotelian way: a rock has them in potency. We know this for certain at least for some rocks because they can be ordered into parts of us. This, actuality of consciousness can be achieved by these minerals if they are ordered in the right way, in the right relationships: if, in other words, they take on the right form.

So the mineral is potentially part of a conscious being; it is thus potentially conscious. But potentiality is first actuality. In order to be potentially conscious, it must actually be the right kind of thing to be absorbed into our form.

Therefore, the rock is first actually conscious, or said another way, potentially so.

Grim said...

That is not the Neoplatonic approach, which is harder to engage. I like it better; but in this way, you can see that it’s easy to get to a proof on Aristotelian terms. Of course the rock is actually capable of consciousness, in a way. It’s just not all the way there because it hasn’t attained the right form for completely actual consciousness.

Tom said...

I was following up to that penultimate sentence. On that, in what way is it actually capable of consciousness? Is that like "It is almost capable of consciousness, but not quite"?

sykes.1 said...

Bacteria can find light and nutrients. Apparently they use gradients in intensity, magnetism, temperature and concentration. Bacteria do this. Why is anyone surprised plants can. Every tree on my hillside lean towards the sun. Sun flowers and others track the sun durinf the day. Moon flowers come out at night. Even Aristotle and the ancients knew this.

All mammals have some degree of consciuosness. Even cats dream.

Grim said...


There are different models. A rock is also potentially part of a house. How much is it an actual house? Well, not very much; but unlike (say) yarn, it could in principle be put into the right form in order to be part of a house. Until it obtains the form, though, it isn't a house in any meaningful sense; it's just more of a house than yarn is. First actuality is crucial, but it may not take you very far toward full actuality.

On the Neoplatonic model, the basic 'stuff' of reality is a consequence of thought in a higher mind (to simplify drastically for discussion). In that sense, of course consciousness inheres in thought.

This has a new plausibility today. What is the most basic sort of matter, the elemental particles, what is that stuff 'made of'? The current standing answer is that things like quarks or electrons aren't so much physical objects like we think of at our own scale, but a kind of interference pattern in some sort of field. (Electrons are often visualized as orbiting a nucleus in the way a moon orbits a planet; but that's not exactly right. In some cases the electron is sometimes on this side of the nucleus, and sometimes that side, but never in the middle. It appears to us as kind of popping in and out of existence, as if you could only see a wave at its peak. Bam! There it is; then it's gone; then, bam!, there it is over there. So the electron is detectable to us, at least, only when the interference pattern is just so; maybe it only properly exists at those instants.)

If that's right, then the most basic sort of stuff that we usually call 'matter' is itself a kind of form: the form being an interference pattern in something even more basic. That looks kind of like what the Neoplatonists called 'prime matter,' as did the middle Aristotelians. But what is that most basic stuff, really? Avicenna has an argument in his metaphysics against it being God. But everything comes to be out of it: the most basic structures are forms of that matter, and everything else comes to be by assembling those forms into other forms (i.e., subatomics into atomic particles; those into molecules; etc.).

On a Neoplatonic reading, consciousness may well be a property of the field. It would then inhere in everything; but like the electron, it might only 'emerge' under the right conditions.

Tom said...

That's interesting. Thank you.