This is my response to a post to a Facebook group post about the idea that plants and animals without brains have consciousness; that plants, and other life forms without nervous systems like ours, might also have it. The comment, albeit popular in a trendy sorta' way, is far from justified. Here's why:
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Moving the Goal Posts:
To start with consciousness isn’t being found in plants. There’s no evidence for that at all. What is happening is that the word itself is being reframed to include more physical processes than intellectual reflection. That’s not new, panpsychism has been around for hundreds of years, probably longer. What’s changed isn’t the "discovery", it’s the cultural redefining of what consciousness is. With all of the obstacles to overcome creating AIs, computer science started taking it seriously, so people stopped laughing at the idea, and that tolerance has spread to neurology and layman speculations about nature; BUT let’s be clear, there is no actual evidence for plant consciousness at all. None. There’s just a social shift to how popular culture is saying it should be defined. The problem being that simple reaction ISN'T consciousness.
When people say “plants are conscious,” what they’re really describing is what a plant does when it’s faced with something that might harm it, but that’s not awareness, it’s an evolved physical response. You grow your hair for evolutionary reasons too, but are you aware of your hair growing? Can you choose for it not to? Are you monitoring the process as it happens
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What Actually is Consciousness?
Consciousness is an evolved, sophisticated result of the need for certain animals to move in complex ways for complex reasons. Take pain, as one example. Why does pain exist? Because when we’re in pain, we move away from it, QUICKLY. That’s its purpose. If you had to analyze pain before reacting, if say you leaned on a stove and had to think about whether to move or not, you’d be badly burned before you finished the thought. Pain bypasses thought. It makes us act now. It evolved due to the need for instant mobility.
A tree can’t move quickly. It doesn’t need pain. It doesn’t need that kind of awareness. ITS strategy is to become strong and massive so to withstand harm rather than avoid it. Grass handles harm by being flexible and abundant; one blade dies, another takes its place, the species survives. There’s no evolutionary pressure there for the kind of awareness pain provides animals. And since all of the emotions function as contextually behavioral presets using mobility as its medium like pain, plants have no reason to evolve those either.
Those preset reactions in us, are the roots of what we call “awareness.” The stored memories of predicted contexts that allows us to adjust our reactions more or less appropriately become our beliefs. And the total structural paradigm of those beliefs along with the emotions and awareness, cause our self-awareness, and our inner life, and THAT’s what we call "consciousness."
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If Plants Don't Think, What Are We Looking At?
Another thing people with this "plants think" idea get wrong is that plants quite literally don’t think or talk to each other. More accurately put, they react to each other through fungi. It’s the fungi doing the coordination, not the plant. So if we want to assign consciousness to something you don't assign it to the foot, you assign it to the brain, if you git what I'm sayin'. Through mycorrhizal symbiosis fungi trade their stability and ability to distribute resources for the plant’s sugar and energy. The fungi decide how nutrients, water, and chemical signals are shared. If you want to talk about something “brain-like,” it’s the fungi, not the tree. The fungi organize the forest. The plant itself just reacts.
And this kind of cooperation; one organism joining with another to create a larger, organized whole; isn’t unique to plants and fungi. It happens between animals and like with pollinators, even between animals and plants. Then there's when one plant or animal survives as a parasite of the other. Interestingly, the prevailing theory is that this is how single-celled life evolved in the first place. One simple cell drifting through the world, over time, adapts to new environments and splits into variations. Two different variations meet again, and as it happens come to work together as it helped them both survive. The ones that don’t cooperate either have to evolve differently to survive or die out, and the ones working together, integrated until eventually one cell absorbed the other. The idea is that, that's how modern cells got their inner mechanisms, like the cell's nucleus, that made them more complex cells than just the simpler walled off sectioned cells that they'd evolved from.
Were those early cells (or even the modern ones) “conscious”? Of course not. They're only cells. But can they react? Absolutely. Reaction and cooperation aren’t awareness. They’re steps toward complexity.
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The Brain Itself is Not Responsible:
The post also brought up the idea that animals without centralized brains have their own consciousness, without a brain, and yeah, I'd have to agree with that. The thing is though, the pivotal mechanism creating consciousness isn’t the brain itself. It’s the nervous system within the brain. The brain works because it’s a highly organized communication network like hardware capable of running complex, shifting contexts. That’s what lets us think and feel. An octopus, as an example, has a distributed nervous system that allows for a similar kind of complexity, even though it’s organized differently than a centralized brain with a spinal cord.
So yes, you can have a brain without consciousness, but you can’t have consciousness without a nervous system (or something equally complex to serve as the hardware) .....even an analogue machine would do the job, it just wouldn't be as quick as what animals have. Plants don’t have that. Their structure simply doesn’t allow for the kind of integrated, layered processing that consciousness requires.
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But We Aren't Plants, How Can We Know For Sure?:
And I think it important to address an argument possibly implied in all of this; the idea that plant consciousness might just be too alien for us to recognize is neither an objective position, nor is it true. That we can’t judge them by our standards because we don’t share the same kind of mind doesn't keep us from a clear analysis and comparison of the mechanisms involved. This idea contradicts itself.
Our definitions of consciousness come from us, from humans observing and describing the world. Plants aren’t taking part in that. The word “consciousness” belongs to the language of beings talking to themselves, not the plants. If you say plants have it, you’re already using the word differently than someone who says they don’t, and in a way that compares what they experience to ours. Their assumptions are in the possibility of that comparison.
It’s not that we can’t know either way, that our hands are tied and we've no choice but to remain agnostic on this. The arguments I've already made stand on their own. It’s that we’re talking about different things entirely. People who side with making the determination rest on a definition of "consciousness" that's precise enough to be used deductively, making this a 'yes' or 'no' answer, while people who side with not making that determination rest on the idea that we don't really know what "consciousness" is.
The thing is, is that while we can't know the intricate details about every last horse that exists, WE ACTUALLY DO have a clear definition of what "horse" means regardless of the infinite focus on those details, and as long as the same can be said for "consciousness", whether anything has it, will be at some point determinable. That is UNLESS, some of us are determined to keep moving the goal posts without considering the mechanism, and the definition keeps becoming blurred.
To hopefully hit this point home, remember the old “how do I know your blue, is my blue?” argument? Sure, we can’t directly feel each other’s experience objectively, without tainting our perspectives with our own individual views, but what we can do is look at the mechanisms that produce them. We can see how the brain processes light, how those processes create the experience of color, and then compare those mechanisms between people. From that, we can define what the “blue” mechanism is, and how we're experiencing the same and different things when the color pops up. The same goes for consciousness. We can see the structures that support awareness, memory, and emotional integration, and plants simply don’t have them. So unless we stretch “consciousness” to mean “anything that reacts,” there’s simply no reason to say plants have it.
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The Popularity of the Idea That They Do:
So why are so many jumping on the bandwagon? It's the other "old" story. People project themselves into everything in order to understand them. It's anthropomorphism 101. Some of us can't even analyze anything without projecting our self centered human traits on to it. It's why prejudices pollute so many of the beliefs of so many of the people you see around you. Whenever you say to yourself "How can this guy be so blinded by this crazy idea?" think about what's happening here and whether there's actually anything at all pointing to the idea that plants can think.