Michael Levin: Hidden Reality of Alien Intelligence & Biological Life | Lex Fridman Podcast #486

- The following is a conversation with Michael Levin, his second time on the

podcast. He is one of the most fascinating and brilliant

biologists and scientists I've ever had the pleasure of speaking

with. He and his labs at Tufts University study and build

biological systems that help us understand the nature of intelligence,

agency, memory, consciousness, and life in all of its forms here on Earth, and

beyond. This is the Lex Fridman Podcast. To support it,

please check out our sponsors in the description, where you can also find

links to contact me, ask questions, give feedback, and so

on. And now, dear friends, here's Michael Levin.

You write that the central question at the heart of your work from

biological systems to computational ones is, "How do

embodied minds arise in the physical world, and what

determines the capabilities and properties of those minds?" Can you

unpack that question for us, and maybe begin to answer it?

- Well, the fundamental tension is in both the first-person,

the second-person, and third-person descriptions of mind.

So, in third-person, we want to understand how do we recognize

them, and how do we know, looking out into the world, what degree of agency there

is, and how best to relate to the different systems that we find.

And are our intuitions any good when we look at something and it looks

really stupid and mechanical, versus it really looks like there's

something cognitive going on there? How do we get good at recognizing them?

Then there's the second-person, which is the control, and that's both for

engineering but also for regenerative medicine, when you want to tell the system to do

something, right? What kind of tools are you going to use? And this is a major

part of my framework, is that all of these kinds of things are operational claims.

Are you going to use the tools of hardware rewiring, of control

theory and cybernetics, of behavior science, of

psychoanalysis and love and friendship? Like, what are the interaction protocols that you

bring, right? And then in first-person, it's this notion of having an inner

perspective and being a system that has valence and cares about the

outcome of things. Makes decisions and has memories and tells a story about

itself and the outside world. And how can all of that exist and

still be consistent with the laws of physics and chemistry and various other things that we

see around us? So that, that I find to be maybe the most interesting and the

most important mystery for all of us to both on the science

and also on the personal level. So that's what I'm interested in.

- So your work is focused on

starting at the physics, going all the way to friendship and love and

psychoanalysis.

- Yeah, although, actually I would turn that upside down. I think that pyramid is backwards,

and I think it's behavior science at the bottom. I think it's behavior science all the

way. I think in certain ways, even math is the behavior of

a certain kind of being that lives in a latent space, and

physics is what we call systems that at least look to be

amenable to a very simple, low agency kind of model, and so

on. But that's what I'm interested in, is understanding that and

developing applications. Because it's very important to me

that what we do is transition deep ideas and

philosophy into actual practical applications that not only make it

clear whether we're making any progress or not, but also allow us to relieve

suffering and make life better for all sentient beings, and enable

to, you know, enable us and others to reach their full potential. So these are very

practical things, I think.

- Behavioral science, I suppose, is more subjective, and mathematics and physics

is more objective? Would that be the clear difference?

- The idea basically is that where something is on that

spectrum, and I've called it the spectrum of persuadability. You could call it the

spectrum of intelligence or agency or something like that. I like the notion of the spectrum of

of the spectrum of persuadability, because it's an engineering approach. It means

that these are not things you can

decide or have feelings about from a philosophical armchair. You have

to make a hypothesis about which tools, which interaction

protocols you're going to bring to a given system, and then we all get to find out how that worked out for

you, right? So you could be wrong in many ways, in both directions. You can

guess too high or too low, or wrong in various ways, and then we can all find out

how that's working out. And so, I do think that the behavior of certain

objects is well-described by specific formal rules,

and we call those things the subject of mathematics. And then there are some other

things whose behavior really requires the kinds of

tools that we use in behavioral cognitive neuroscience, and those

are other kinds of minds that we think we study in

biology or in psychology or other sciences.

- Why are you using the term persuadability? Who are you persuading, and of what?

- Well-

- In this context.

- Yeah, the beginning of my work is very much in regenerative

medicine, in bioengineering, things like that. So

for those kinds of systems, the question is always, how do you get the

system to do what you want it to do? So there are cells, there are molecular

networks, there are materials, there are organs and tissues and synthetic

beings and biobots and whatever. So the idea is, if I want your

cells to regrow a limb, for example, if you're injured and I want your cells to regrow a

limb, I have many options. Some of those options are I'm going to

micromanage all of the molecular events that have to happen, right? And

there's an incredible number of those. Or maybe I just have to micromanage the

cells and the stem cell kinds of signaling factors.

Or maybe actually I can give the cells a very high-level

prompt that says, "You really should build a limb," and convince them to do

it, right? And so which of those is

possible? I mean, clearly people have a lot of intuitions about that. If you ask

standard people in regenerative medicine and molecular biology, they're going to say, "Well, that

convincing thing is crazy. What we really should be doing is talking to the cells, or better

yet, the molecular networks." And in fact, all the excitement of the

biological sciences today are at single molecule approaches and

big data and genomics and all of that. The assumption is that,

going down is where the action's going to be, going down in scale,

and... I think that's wrong. But the thing that we can say

for sure is that you can't guess that. You have to do

experiments and you have to see because you don't know where any given system is on

that spectrum of persuadability. And it turns out that every time we look and we

take tools from behavioral science, so learning different kinds of

training, different kinds of models that are used in active

inference and surprise minimization and perceptual multi-stability

and visual illusions and all these kinds of interesting things. Stress

perception and memory, active memory reconstruction.

All these interesting things. When we apply them outside the

brain to other kinds of living systems, we find novel discoveries

and novel capabilities, actually being able to get the material to do new things that

nobody had ever found before. And precisely because I think

that people didn't look at it from those

perspectives, they assumed that it was a low-level kind of thing. So when I say

persuadability, I mean different types of approaches, right? And we all

know if you want to persuade your wind-up clock to do something,

you're not going to argue with it or make it feel guilty or anything. You're going to have to get in there with a wrench and you're gonna have

to, you know, tune it up and do whatever. If you want to do that same thing to a

cell or a thermostat or an animal or a human, you're going to be using

other sets of tools that we've given other names to. And so that's... Now,

of course, that spectrum, the important thing is that as you get to the right of that spectrum, whereas the

agency of the system goes up, it is no longer just about persuading it to do

things. It's a bidirectional relationship, what Richard Watson would call a mutual

vulnerable knowing. So the idea is that on the right side of that

spectrum, when systems reach the higher levels of agency, the idea is

that you are willing to let that system persuade you of things as

well. You know, in molecular biology, you do things, hopefully the system does what you want to

do, but you haven't changed. You're still exactly the way you came in.

But on the right side of that spectrum, if you're having interactions with even cells, but

certainly, you know, dogs, other animals, maybe other

creatures soon, you're not the same at the end of that interaction as you were

going in. It's a mutual bidirectional relationship. So it's not just you persuading

something else, it's not you pushing things. It's a mutual

bidirectional set of persuasions, whether those are

purely intellectual or of other kinds.

- So in order to be effective at persuading an

intelligent being, you yourself have to be

persuadable. So the closer in intelligence you are to the thing you're trying

to persuade, the more persuadable you have to become, hence the mutual

vulnerable knowing. What a term.

- Yeah. Richard, you should talk to Richard as well. He's an amazing guy and he's got

some very interesting ideas about the intersection of cognition and

evolution. But I think what you bring up is very important because,

There has to be a kind of impedance match between what you're looking for and the tools that

you're using. I think the reason physics always sees mechanism and

not minds is that physics uses low agency tools. You've got

voltmeters and rulers and things like this. And if you use those tools as your

interface, all you're ever going to see is mechanisms and those kinds

of things. If you want to see minds, you have to use a mind, right? You have to have

some degree of resonance between your interface and the thing you're hoping to find.

- You said this about physics before. Can you just linger on that and expand on it,

what you mean, why physics is not enough to

understand life, to understand mind, to understand intelligence? You

make a lot of controversial statements with your work. That's one of them 'cause there's a lot of

physicists that believe they can understand life, the emergence of life, the origin of

life, the origin of intelligence using the tools of physics.

In fact, all the other tools are a distraction to those

folks. If you want to understand fundamentally anything, you have to start at

physics to them. And you're saying, "No, physics is not enough."

- Here's the issue. Everything here hangs on what it means to

understand, okay? For me, because to understand doesn't just mean have some sort of

pleasing model that seems to capture some important aspect of what's going

on. It also means that you have to be generative and creative

in terms of capabilities. So for me, that means if I tell you this

is what I think about cognition in cells and tissues, it means, for example,

that I think we're going to be able to take those ideas and use them

to produce new regenerative medicine that actually helps people in various ways, right?

It's just an example. So if you think as a physicist you're going to have a

complete understanding of what's going on from that

perspective of fields and particles, and, you know, who knows what else is

at the bottom there.

Does that mean then that when somebody is missing a finger or has a

psychological problem, or you know, has these other

high-level issues, that you have something for them, that you're going to be able to do something?

Because my claim is that you're not going to, and even if,

even if you have some theory of physics that is completely compatible with

everything that's going on, that is... it's not enough. That's not specific enough to enable you

to solve the problems you need to solve. In the end, when you need to solve those problems,

the person you're going to go to is not a physicist. It's going to be either

a biologist or a psychiatrist, or who knows, but it's not going to be a

physicist. And the simple example is this. You know, let's say,

let's say someone comes in here and tells you a beautiful mathematical proof, okay?

It's just really, you know, deep and beautiful, and there's a physicist nearby, and he

says, "Well, I know exactly what happened. There were some air particles that moved

from that guy's mouth to your ear. I see what goes on. It moved

the cilia in your ear and the electrical

signals went up to your brain." I mean, we have a complete accounting of what happened, done and

done. But if you want to understand what's the more important

aspect of that interaction, it's not going to be found in the Physics Department. It's going to be found in the Math

Department. So that's my only claim is that physics is an amazing lens with which

to view the world, but you're capturing certain things, and if you want to

stretch to sort of encompass these other things, it

just, we just don't call that physics anymore, right? We call that something else.

- Okay. But you're kind of speaking about the super

complex organisms. Can we go to the simplest possible thing where you first

take a step over the line, the Cartesian cut, as you've called it, from the

non-mind to mind, from the non-living to living?

The simplest possible thing, isn't that in the

realm of physics to understand? How do we understand that first step where

you're like, that thing is no mind, probably non-living, and

here's a living thing that has a mind. That line.