Is there a consequence of your thinking?

I don’t think it’s arbitrary. There’s a clear distinction between say a rock and a cell, even if you view the rock on geological timescales and the cell on biological timescales. I don’t think it’s arbitrary or even surprising that humans view things from our own vantage point in reality.

There's a negative consequence - If the line between life and non-life is blurry, that means there isn't a clear place for souls to fit in. If life can be completely explained as an emergent property of individual non-living parts, (ultimately, atoms aren't alive, even though they make up living things) then we can't tell whether souls exist in our universe or not.

This isn't a big deal for science, but it's a moral victory for atheists.

> If the line between life and non-life is blurry, that means there isn't a clear place for souls to fit in

If "souls" aren't defined precisely enough that there's an experiment that give different results depending on whether they exist, then the statement "souls exist" is meaningless, and anyone saying it is not even wrong.

> This isn't a big deal for science, but it's a moral victory for atheists.

Theists won't care, although I suppose some will mutter something about separate magisteria.

The concept of a soul is a rich one, and for many people is largely metaphorical or figurative. You can subscribe to a materialist account of our cosmos and still draw meaning from the idea of a soul.

I am hesitant to agree that it's a moral victory - maybe it's more of a victory about metaphysics? (also, what is a metaphysical victory? :))

a metaphysical victory for atheists who consumes the concept of soul would be that the concept ceases, which is equivalent to its physical death in the competing theist's view, and completely unconsequential to the atheist, which only proves that atheism is at least not that bad.

That isn't necessarily true. All you have to do to keep the concept of external soul alive is to accept the idea of simpler souls. Maybe there isn't am irreducibly complex soul.

Moral victory for atheists sounds like an oxymoron. Atheists don't need victories - there is nothing to prove - and atheism is amoral.

I guess mean arbitrary in the sense that being born as a human is kinda arbitrary, in the sense that individual human perspectives themselves are arbitrary amongst the vast range of possible ways to experience or perceive, both human and beyond human.

Well and also in the sense that it takes some pretty arbitrary decisions to distinguish living from nonliving.

I don't mean that these distinctions are useless or unimportant, just that for the most part they may not be all that fundamental... You end up drawing lines in the sand.

For example, are you gonna exclude viruses from the tree of life? Why? Because viruses don't have any known local macroscopic motility? Because they rely too heavily on their environment ("host") to reproduce? Those are summaries of the arguments I've heard against viruses being alive, and imo they're pretty arbitrary.

On the other hand, viruses reproduce and are subject to selective pressures, as are most phenomena with a lifecycle and an external environment. So then if you include viruses are you gonna include RNA? What about reactions, e.g. combustion? Are these alive? Well then and what about consumer product/producer systems? Don't they have lifecycles of their own? Some feedback loops that cause selective pressures? Environments to survive and reproduce in?

It's fuzzy.

A lot of rational, materialistic categorizations of living vs unliving look to me like hunches based on assumptions about motility or consciousness, and might as well be reframed as "does it move?" or "can I communicate with it?" or "does it see me?"

Lynn Margulis and Dorion Sagan wrote a nice essay called "the uncut self" that's really great and related to this in my view. It's all about where the tendency to draw boundaries around "individual selves" when looking at living systems, boundaries that might not be so fixed or obvious when you look carefully.

I think it's simpler than you're allowing. Death in animals is the absence of consciousness with no possibility of recovery. In plants and maybe-but-probably-not-sentient life, it's more complicated.

We all agree when we should say that a cow is dead, but what about sponges? You can pass a sponge through a sieve, and the isolated cells will recombine https://www.shapeoflife.org/video/sponges-time-lapse-sponge-... (Is there a better link?) Can a single cell of a sponge create a "new" sponge? Or it's just the "old" sponge? Should you wait until the last cell is dead until we can claim it's dead?

Back to cows...

You can remove the heart of a cow and keep the heart alive in a proper device, and keep the rest of the cow alive with an artificial heart. (I don't know if someone has tried this with cows, but this should be possible with the same technology for hearts transplants in humans.)

Are both parts alive? What happens if I unplug one of them? Is the heart-less-cow is the real cow? I think we all agree about this last question, but from the cellular level it's just an arbitrary classification, in spite it's useful for us.

It's not a matter of arbitrary classification in the cow case. The original definition still works. The heart has no experience. The continuum of consciousness exists solely within the heartless cow. Whether you want to call the heart "alive" is the same as the question about plants and sponges.

Do we know that the heart has no experience?

What level of complexity is required for experience?

Experience is not a function of a simple "level of complexity" but of structure with specific function. The idea that you reach a certain level of complexity and just get sentience as an incidental side effect of the complexity is a fallacy for multiple reasons. Sentience results from structures specifically crafted to create sentience. In the 21st century as opposed to the 12th century we know for sure that the structures that give us sentience reside entirely in the brain. We can examine the highly complex structure of the heart and compare it to the brain and see that while the heart is complex it does not have the same structure as the brain. The heart is not sentient not because it lacks sufficient "level of complexity" but rather because it lacks a specific functional form of complexity, i.e. the heart lacks information processing structures that the brain has. We can also observe things like when there is a heart transplant the recpient does not start experiencing a change in personality from an independent "sentient" donor heart. Thus there is no evidence that sentience resides outside the brain, so why assume it might?

You could just as well assume that a rock has the processing power of a computer CPU but it just lacks input and output.

Having a complex brain is one way to achieve sentience. It might not be the only way.

The heart of a cow (and any vertebrate) can beat on it's own. Each muscular cell of the heart beats, and they coordinate the beating when they are in contact. Also, there are a lot of neurons in the heart to synchronize the beating of the different parts of the heart.

IIRC It can keep beating even without brain signals. It's not the ideal rate of beating, and there are other problems, but the heart somewhat beats on it's own.

I don't know how many sensing neurons the heart have and how they interact with the beating. The heart is not as "smart" as a brain, but it's "smarter" than a rock.

Stealing the examples from other comments: Is the heart of a cow smarter than a planaria? Is the heart of a cow smarter than a hydra?

Yeah the heart can beat according to its internal pace maker and a CNC machine can move about and cut a work piece according to its internal program. We have no reason to believe that either is sentient. Maybe a thousand or so years ago when people did not fully understand that the brain is where consciousness takes place. Nowadays there is no excuse. Autonomy is not sentience. Your heart does not have feelings or a sense of self. Evolution did not require that to build a somewhat self regulating muscular pump. The rock vs. cpu example was a little hyperbolic I guess.

My point is simply the presence of interconnected neurons running a certain program is not sufficient to give rise to sentience or conciousness. I believe what we call sentience or conciousness is not an accident or even really an "emergent" phenomenon but rather the direct, purposeful result of specific structure that was selected for by evolution.

The phrase "level of complexity" is inartful because it implies there is one axis or dimension to complexity when that is not the case. If you make a random soup of 100 billion interconnected neurons and teach it to classify images it is highly unlikely that you will get a sentient being by accident although you may have a very efficient neural network at the task it was designed for. If however you take a 100 billion neurons and subject them to the selective pressures of evolution in the real world, where a sentient or self aware self may have advantage then it is not unlikely perhaps that you end up with a sentient or counscious being. Thus sentience is the result of specific selected for structure not the random outcome of a certain level of complexity. I don't see why this is even contraversial.

General intelligence does not exist divorced from the real world and it does not just happen as the side effect of a certian "level" of complexity.

With regard to the question is the heart of a cow smarter than a planiar (worm) whole organism I do not see this as a meaningful question because the starting premise is wrong. The starting premise assumes that there is some abstract quality "sentience" or "intelligence" that exists on a single axis, a continuum of "levels." I'd say the axis does not exist, there are no levels, what matters are functions and it is not meaningful to argue whether or not the planarian or the heart is at a higher level of intelligence because the preform different functions. Notably one is a free living creature while another is an organ inside another creater. I think they are incomparable. Neither has the specific brain structure that gives humans and other higher animals sentience so it does not make sense to argue whether one or the other is at a higher level when neither is at any level at all in terms of a structural or functional comparison with a brain. A worm is not further ahead or behind a heart when compared to a brain because neither is anything like a brain. Maybe a plannarian can learn. I doubt a heart can learn but maybe it can. But overall the idea of levels of sentience or sentience simply emerging from complexity that does not intentionally provide for it is silly in my opinion.

> I doubt a heart can learn but maybe it can.

That's a very interesting question! (Do we have here some biologist that can try it?)

The difference between an isolated organism and a part is sometimes no so clear. For example in Clonal Colony https://en.wikipedia.org/wiki/Clonal_colony Is each trunk of Pando a different organism? Why not each branch? (Plants do very nasty things to other plants, but in slow motion. It's nice to see time lapses videos of plants "fighting".) Most examples of clonal colonies are plants, some of them have specialized members and some have identical members. If you prefer animals, one nice example is https://en.wikipedia.org/wiki/Portuguese_man_o%27_war

That’s a truly meaty take on the Ship of Theseus[1] problem. In my mind, like so many philosophical problems, the fundamental distinguishing point is materialism vs dualism. For the materialist different matter means different ship. For the dualist the matter is just expressing an ideal. I’ve heard that in Asia there are temples that were totally destroyed and then rebuilt and everyone considers them as old as since their first building date.

[1] https://en.m.wikipedia.org/wiki/Ship_of_Theseus

My favorite example of this is the planarian. You can cut its head in half and it will generate two new halves. Same with the tail. Or cut the whole thing into pieces, and each piece will regenerate the whole body.

The hydra too. Me and a friend used to pass time doing debates, and when one of us was too tired to research or argue we'd debate about dumb stuff, and I was a stalwart "the original hydra reproduced into two offspring" much like how single celled organisms "die" when they reproduce

You can think of insect hives (bees, ants, etc) as a single organism that happens to not be physically contiguous.

The individual insects in a hive are typically 75% identical genetically.

And some might say “but the hive itself doesn’t have consciousness, or an ‘experience’”. Which is impossible for you to know, unless you are (or have been) a hive.

If you attack the hive, it definitely defends itself. It looks for food, etc...

It is popular to admire the selfless ants or bees who willingly give their lives for their society.

But if you think of them as cells of an organism, that happens in every living being.

When you see a hive sacrificing itself, we can talk :)

This is an example of the greyness that the article discusses. If hives are to be seen as distinct life, it will be quite close to the end of a spectrum.

The end of the spectrum is probably more at thinking of human cities as distinct life forms.

How similar are city and hive?

The "possibility of recovery", as you put it, is a moving target depending on the specific situation and the technology involved. For some examples: https://www.wired.com/2014/07/revive-the-dead/

The point being that as technology continues to develop in this area, our understanding of when someone is "dead" may also continue to shift.

There's also the classic example of comatose people.

Decay still gives you a hard deadline, unless you freeze the body a la cryogenics. But that's a long shot.

I don't think we should mix in consciousness in the definition of life. It is hard enough as it is also without consciousness mixed in.

Origin of life and origin of consciousness are as I see it the two major mysteries of the universe. I see them as separate.

That's a good thought - but worth considering that just because lines are fuzzy doesn't make them either 'arbitrary' or even 'subjective'.

That a materialist perspective gives us some nice hard rules for understanding certain things, it also by definition struggles to help us understand the nature of other things, i.e. 'most important bit' which is 'life' itself, so maybe we should be thinking about that problem a little bit differently. 'Emergence' seems to be a least one idea, among many.

> That's a good thought - but worth considering that just because lines are fuzzy doesn't make them either 'arbitrary' or even 'subjective'.

Interesting and plausible, but you didn't give an argument or any example for that.

For most things in the real life that we categorize, the rules that distinguish those categories can be vague. It doesn't mean those categories are not valid, or a function of 'human perception'.

We have difficulty with biological distinction, but we can still confidently categorize something as being a 'Horse' and 'Not A Horse' ... even if sometimes it's a little bit ambiguous, aka 'Kind of a Horse'.

Edit: and as for 'other ways of thinking' it very quickly goes into metaphysics so it's hard to talk about because we don't spend much time in that realm. 'Emergence' and 'Biocentrism' are interesting ideas (fields?) that sit within more or less regular bounds of science and so they're just examples of what I'm referring to.

I think you'd have to define what it means for a category to be valid. The way I see it is that a category is either useful or not and whether it is or not depends on our goals which depends on what we like and want which is subjective and the judgement itself relative to such a system so designed. That's not to say they are arbitrary, because they're objectively useful or not with respect to the goal.

I don't think biologists would agree with you about the horse. It's actually consider a crisis in the philosophy of biology that the concept of species is ill-defined. [1] Like I said, the resolution to me is pragmatic: the definition will depend on whether it is effective relative to some purpose.

1. https://plato.stanford.edu/entries/species/

A biologist would only take umbrage rhetorically, which is fine, but they'll never categorize a rock, a flower, or a human as 'a horse' so in reality it's not a problem.

While 'value' is surely in the eye of the beholder ... whether or not something fits into the category is not as subjective.

And frankly, the 'big question' is 'who is the beholder' - which is something that materialism is struggling to tell us.

We might as well just link to the basic problem statement rather than recapitulate 3000 years of philosophy: https://en.wikipedia.org/wiki/Sorites_paradox

> We have difficulty with biological distinction, but we can still confidently categorize something as being a 'Horse' and 'Not A Horse'

A paleontologist might disagree with you.

Why not go further and say the entirety of "our reality" is a human hallucination, as our senses are limited and our brains peculiar in how they process their inputs. That the "real reality" is an imperceptible-to-us dance of fields (even that is only as far as our theories take us).

At the risk of sounding like a hypocrite after my "Not finding souls is a victory for atheism" comment:

What does that add? Do we have better models if we say we're all hallucinating the same seemingly-kind-of-objective reality?

What if I'm the only human, you're all p-zombies, BUT all dogs are conscious?

Lots of loaded words in the comments, and hallucination probably takes some of us to places that aren't helpful, but understanding the limits of our perception and understanding gives us better context. Even if we don't understand the limits, it's helpful to know that our reality and reality are separate things. If we don't know we have blind spots, we won't know to check them.

We are all p-zombies, and we voted at our supper club to determine that you don’t actually exist.

>"their meaning is inherently embedded in human experience."

Not necessarily, some animals have the same perception. Some carnivores don't eat dead animals, others primarily eat carrion and they interreact differently with inanimate objects.

> Just to clarify, I don't mean that these distinctions are meaningless, just that their meaning is inherently embedded in human experience.

In that case, describing the distinction as "arbitrary" seems wrong.