welcome everyone I'm your host Emerson green so Sean Carroll physicist and author of the big picture has a go-to argument that works like a skeptical Swiss army knife whether your target is the soul or the afterlife or even psychokinesis this one argument can do it all so it starts with a dramatic sounding claim the laws underlying the physics of everyday life are completely understood he's defended this claim in a series of blog posts lectures interviews and published papers there's also a t-shirt according to Dr Carol this isn't as ostentatious of a claim as it may sound at first blush the macroscopic objects we interact with are composed of atoms and acted on by familiar forces and we know how those particles and forces work sure we don't understand the full theory of quantum gravity but we understand it perfectly well at the everyday level in his blog post the world of everyday experience in one equation he says quote no experiment ever done here on Earth has contradicted this model in another post entitled seriously the laws underlying the physics of everyday life really are completely understood he adds electrons obey the same equations of motion whether they are in a rock or in a human heart end quote so the argument is roughly you are made of atoms we know how atoms work and atoms work the same way regardless of what larger structure they constitute and for that reason there's just no room for anything beyond the materialism he advocates we can discard any notion of an immaterial mind that's causally connected to the body likewise we can cast aside more radical parapsychological claims without the annoying business of investigating the subject too closely since we already know it must be wrong Carol's view seems to be that this argument if successful would rule out a raft of possibilities at once of course he recognizes that science is tentative nothing is ever certain and there can be future Revolutions in our understanding of nature he's not claiming to have ruled out anything with absolute certainty nor is he claiming that physics is somehow complete rather the domain of physics relevant to Everyday human life is well established enough that we can say with a very high degree of confidence that there is nothing non-physical paranormal or Supernatural at work in our world of protons neutrons and electrons Dr Carol thinks we should conclude that the natural phenomena of our world everything from brains to social systems are entirely constituted and determined by the microphysical given the empirical success of the core Theory basically if there were any forces entities Etc that exerted a causal impact on the everyday physical world of spoons and fleshy organisms physicists would have found experimental evidence of their influence by now according to Carol it's completely implausible that quote the laws of physics that have been tested by an enormous number of rigorous and high Precision experiments over the course of many years are plain wrong in some tangible macroscopic way and nobody ever noticed much more likely he says those who think they have something that contradicts the laws of physics relevant to Everyday Life have probably just done some careless research Fallen prey to confirmation bias or trusted unreliable testimony so here's a summary of the argument from the abstract of Carol's paper the quantum field theory on which the everyday World supervenes quote effective field Theory EFT is the successful Paradigm underlying modern theoretical physics including the core theory of the standard model of particle physics plus Einstein's general relativity I will argue that EFT grants us a unique Insight each EFT model comes with a built-in specification of its domain of applicability hence once a model is tested within some domain of energies and interaction strengths we can be confident that it will continue to be accurate within that domain currently the core theory has been tested in regimes that include all of the energy scales relevant to the physics of everyday life biology chemistry technology Etc therefore we have reason to be confident that the laws of physics underlying the phenomena of everyday life are completely known so I want to emphasize I want to make a little bit of an argument a very very very little bit of an argument for the statement made in read that we know how Adams work the point is that the laws of physics we don't know all laws of physics by any stretch of the imagination but those laws of physics that are relevant to the atoms in your body we know all the laws of physics that far there's no room for new laws of physics that would affect how the atoms in your brain actually work that's a very subtle statement so I could you know I think that uh Dan mentioned I had three hours to give this talk so I'll so but I I would get tired if that happened so I would give you the whole explanation for the laws of physics how they came to be why we're confident but instead I will just intimidate you in submission by showing you an equation so in this one equation our summarized all of the laws of physics necessary to understand the atoms in your brain at the energy mass and length scales relevant to your everyday lives we have quantum mechanics we have SpaceTime we have gravity we have the other forces electromagnetism and the nuclear forces we have the matter the electrons and the quarks of which you are made and we have of course the higs BOS on Weis CED Pig bow on fans also uh 2 years ago um the point is again there's plenty of room in the laws of physics for other stuff we don't know how black holes work there's plenty of things we don't understand I'm not saying that physics is done I'm a physicist I know it's not done I'm not going to retire soon but we know enough to say that if there are any other forces particles Fields phenomena they can't affect the atom in your brain because either they're so weak that they would have no effect on what the atoms are doing or we would have found them in experiments those are the only two options so to not no one ever understands me when I say this so I'm going to say the same thing over again here are the caveats to this statement I'm not saying we understand all of physics I'm not saying that there's room for no new discoveries in the non- everyday world I'm not even saying we know how the fundamental laws come together to make complicated macroscopic things like frogs and ecosystems and spiral galaxies there's enormous amounts of work to be done in understanding how science works but we have an underlying framework which we call Quantum field Theory as Dan mentioned and Quantum field theory is either true or false all the evidence says that it's true and if it is true then there is no room for new physics that can bu that can in any way fact what goes on in the atoms in your brain we understand what they do there is therefore no room for the information that is you to persist after you die he uses this argument I'll call it the argument from the core theory in a million different contexts many of them related to Consciousness he uses it to argue against the afterlife the soul psychokinesis levitation pans psychism and against far more specific philosophical views like the idea that rationally responding to one's value judgments or conscious inclination is a fundamental form of causation like I said Swiss army knife lest I be accused of straw Manning before I go into criticizing the argument let me take one more stab at explaining the chain of reasoning here why do Defenders of the Core Theory argument think it rules out say an immaterial Soul well dualists typically believe that the soul has causal effects on the body the body is made of atoms but the dualist is telling us that atoms behave differently as a result of the influence of the soul imagine if we chose a subatomic particle to ignore completely in all our experiments our predictions wouldn't pan out since we're ignoring a particle that exerts a causal influence on what we're observing and yet this isn't currently happening even though we are ignoring this influential Soul stuff if we just removed any mention of protons from our standard model of the stuff that exists in our everyday world what we observe in experiments would stop making sense because protons make a difference mental substance is a very physically influential substance it supposedly makes a difference so you'd think there'd be some physical evidence for it the reply is that dualists only think mental substance makes a difference in certain macroscopic systems their view doesn't predict that we would see its influence in the microphysical world when it's not a part of those macroscopic systems when was it ever a part of the dualist view that the soul would influence the events in a particle accelerator the idea that actually needs to be defended is that atoms behave the same way regardless of what larger system they constitute that is what's in dispute in other words what needs to be defended is micro reductionism on micro reductionism what a human being does is ultimately fixed by the fundamental particles making them up and the behavior of the fundamental particles making them up is entirely determined by the basic laws of physics as Carol put it electrons and other particles obey the same equations whether they are inside a rock or inside a human brain so that is the crucial step and it can't be tested in a particle collider if we're trying to figure out whether atoms behave in the same way in microscopic and macroscopic systems you can't just test the microscopic systems if there are novel entities or forces or causal principles that only Arise at higher levels of organization and complexity the microphysical and isolation is going behave the same way regardless so before we can dig deeper into why the core Theory argument is flawed we need to grasp a division Carol makes between weak emergence and strong emergence weak emergence is compatible with if not just another name for reductionism but strong emergence is anti-reductionist in philosophy strong emergence is often just called emergence but we'll stick with Carol's slightly non-standard use of terms here as he said in 3: a.m. magazine I think emergence is absolutely Central to how naturalists should think about the world and how we should find room for higher level Concepts from tables to Free Will in a way compatible with the scientific image but weak emergence not strong emergence that is simply the idea that there are multiple theories languages vocabularies ontologies that we can use to usefully describe the world each appropriate at different levels of course graining and precision I always return to the example of thermodynamics fluids energy pressure entropy and kinetic theory collections of atoms and molecules with individual positions and momenta here we have two ways of talking each perfectly valid within a domain of applicability but with the domain of one Theory thermodynamics living strictly inside the domain of the other kinetic theory crucially the emergent higher level Theory can exhibit features that you might naively think are ruled out by the lower level rules in particular thermodynamics famously has an arrow of time defined by the second law entropy increases in isolated systems whereas the microscopic rules of the lower level Theory are completely time symmetric and aolis I think this example serves as a paradigm for how we can connect the Manifest image to the scientific image sure there's nothing like Free Will anywhere to be found in the ultimate laws of physics but that's not the only question to ask at the higher level description we should ask whether our best emergent theory of human human beings includes the idea that they are in the right circumstances rational decision-making agents with freedom of action until we come up with a better description of human beings I'm perfectly happy to say that Free Will is quote unquote real it's not to be found in the most fundamental ontology but it's not incompatible with it either it's simply a crucial part of our best higher level vocabulary end quote in a future episode I want to really dig more into the poetic naturalism defended in Carol's book the big picture because it's really interesting for now we just need to understand that strong emergence is not Kosher but weak emergence is Central to Carol's worldview as he puts it little things can come together to make big things and those big things can often be successfully described by an approximate theory that can be qualitatively different from the theory of the little things end quote for example an atom is just a collection of protons neutrons and electrons atoms emerge in the weak sense the language of atoms is just a convenient way of talking about collections of subatomic particles it's the same stuff that was already there prior to the formation of the atom so there's been no ontological addition to the physical world when subatomic particles come together to make atoms weekly emergent phenomena don't involve anything over and above their constituent Parts strongly emergent phenomena by contrast involve novel entities or forces or powers that arise at higher levels of complexity in organization such that the new behaviors couldn't be derived from the individual behaviors of the constituent parts of the system as Philip Goff elaborates strong emergentists believe that certain complex systems such as conscious brains have novel causal capacities that could not be predicted from knowledge of their basic components imagine a super intelligence of the kind imagined by llas who has total knowledge of the particles and Fields covered by the core Theory at time T and tries to work out the state of my brain at t+1 solely on the basis of the core theory if strong emergence is true that super intelligence will make some false predictions about the locations of the particles in my brain at t+1 as it is relying entirely on the core Theory and is ignorant regarding the contribution of the emergent causal capacities of my brain end quote so if you make an argument for micro reductionism you've made an argument against strong emergence Carol makes an argument for micro reductionism the argument from the core theory in a nutshell we've been looking long and hard at the physical world with advanced technology running experiments and particle accelerators that test the effects of extent particles and forces and anything strong enough to exert a causal impact in the domain relevant to our everyday World which is what's claimed by dualists parasyn exist B it exists but it's too weak to produce the effects claimed or C it's strong enough to produce those effects and there should be physical evidence of its influence on the material world but we don't see those effects so it must be a or b so what's the problem with the argument the problem with the argument is that the experimental evidence cited does not actually support micro reductionism strong emergence would work roughly like this natural laws which exist in addition to the ones currently well understood describe novel entities or forces or powers or causal principles that apply at higher levels of complexity but only at those higher levels of organization so testing the lower levels of organization does nothing to cast out on the existence of these other natural laws causal principles Etc the microphysical would behave in the same way whether there was strong emergence or not this is not some kind of ad hoc adjustment to the theory tailored to dodge the evidence it is just straight up not a part of the theory that the microphysical world being tested in particle colliders would behave differently as a consequence of laws that only apply to higher order systems you just didn't understand the Emergen dis position if you thought this was some kind of knockdown argument so it's sometimes asserted that conservation of energy that energy cannot be created or destroyed rules out strong emergence since strong emergence seems to be an example of the total amount of energy in a system increasing but as David papau explains the conservation of energy in itself does not tell which basic forces operate in the physical Universe are gravity and impact the only basic forces what about electromagnetism nuclear forces and so on clearly the conservation of energy as such leaves it open exactly which basic forces exist end quote so long as emergent mental forces operate in such a way as to pay back all the energy they borrow and vice versa papanau argues they have acted conservatively adding fundamental forces or causal principles does not mean violating conservation it doesn't really even mean that physics is wrong the laws underlying everyday life are true as far as they go they're just incomplete moreover Nancy cartrite has argued that physical laws involve an implicit cedus parabus Clause the laws of physics specify what will happen all things being equal and in the cases we've been discussing all things are not equal if cartrite is correct about these semantic point then those who reject micro reductionism are not really even departing from the predictions associated with quantum mechanics but even if you disagree with her view that the laws of physics specify what will happen all else equal strong emergentists can just embrace the alternative supplementing or expanding the inventory of the natural world is a far cry from simply saying physics is wrong in the conscious mind mind David Chalmers uses the analogy of electromagnetism to quell potential worries about modifying physics quote in a way what is going on here with Consciousness is analogous to what happened with electromagnetism in the 19th century there had been an attempt to explain electromagnetic phenomena in terms of physical laws that were already understood involving mechanical principles and the like but this was unsuccessful it turned out that to explain electromagnetic phenomena features such as electromagnetic charge and and electromagnetic forces had to be taken as fundamental and Maxwell introduced new fundamental electromagnetic laws only this way could the phenomena be explained in the same way to explain Consciousness the features and laws of physical Theory are not enough for a theory of Consciousness new fundamental features and laws are needed this view is entirely compatible with a contemporary scientific worldview and is entirely naturalistic on this view the world still consists in a network of fundamental properties related by basic laws and everything is to be ultimately explained in these terms all that's happened is that the inventory of properties and laws has been expanded as happened with Maxwell further nothing about this view contradicts anything in physical Theory rather it supplements that theory end quote the Crux of the issue to reiterate is that the success of the core Theory doesn't get you within a mile of micro reductionism the experimental conditions in which we've tested the core Theory do not include complex biological systems so contrary to what is often asserted we have not been given strong empirical grounds to reject strong emergence in the brain as Carol himself admits quote particle physics experiments typically examine the interactions of just a few particles at a time so new physical laws that only kick in for complex agglomerations of particles are not necessarily ruled out by the data we currently have surprisingly enough in his 2021 reply to Philip Goff in the Journal of Consciousness studies he concedes this crucial point which seems to undermine his entire case so let's read what he says in context since it is such a major concession quote one is of course free to contemplate whatever extravagant deviations from contemporary physics one likes particle physics experiments typically examine the interactions of just a few particles at time so new physical laws that only kick in for complex agglomerations of particles are not necessarily ruled out by the data we currently have it's worth noting however how profound a departure such laws would represent the most fundamental principle of quantum field theory is locality fields at any one point in SpaceTime are only influenced by the values and derivatives of other fields at that same point not the behavior of fields at other points modifying the dynamical equations in ways that were sensitive to the complexity of a configuration of surrounding particles would represent a dramatic overthrow of this principle end quote an overthrow I can tolerate but a dramatic overthrow I can see an overthrow departing I mean sure what's wrong with the I mean let's depart who hasn't departed but I mean a profound departure it's gone too far I mean this all seems a little bit less convincing than the slam dunk it's usually presented as besides the worries about modifying physics are overblown which was part of Cher's point we're supplementing we are adding to the inventory of nature to best explain the data okay Emerson didn't Carol try to argue the core Theory just stipulates that it applies in biology yeah so look it is sure the core Theory does does rule out strong emergence fine the core Theory does rule out strong emergence but my point is if your starting point is experiments of particle physics and this philosophical evidence for strong emergence the rational thing to do is look for a theory that accommodates both and you're not going to be led to the core Theory you you're not going to be led to something a million miles you're going to be led to a modified version of it where locality is is in a more limited domain of applicability and sure I mean he actually in his paper responding to my book he actually suggests some ways in which the call Theory could be modified to allow for strong emergence um so I think you'd be led to that I mean it would be different if as I say this is not just saying oh we're going to accept the philosophy hell or high water you know empirical evidence counts for nothing the point is these are not conflicting the evidence from particle physics experiments can't possibly cast out on strong emergence because thinking in basy in terms you would not expect strong emergence to be evident if you just talking about dealing with small numbers of particles by definition it emerges in complex systems is G put it elsewhere in a reply to Carol Carol is right that the strong emergentist is obliged to do some serious theoretical work but this theoretical work could be conceived of as explaining how the causal capacities of strongly emergent holes interact with the causal capacities of particles fields to co-determine what will happen understanding strong emergence in this way gives us a response to Carol's novel argument that quote based on Purely physical grounds rather than consciousness-based motivations our expectation that laws of quantum field Theory might break down in biological organisms would be very low indeed maybe so but we should think of strong emergence not as Quantum field Theory breaking down but as a new neurobiological Theory kicking in and the place to look for when emergent neurobiological principles kick is not physics but neurobiology people get very excited about brain scans but in fact they are very low resolution each pixel of an fmri image corresponds to 5.5 million neurons between 2.2 and 5.5 * 10 10 synapses 22 km of dendrites and 220 km of axons we are only 70% of the way through putting together a complete connectome of a maggot's brain with its 10,000 neurons the idea that we know enough about the workings of the human brain with its 86 billion neurons to know whether or not its workings involve strong emergence is not credible end quote suppose a biologist discover is what she thinks is an indispensable law of biology but it's not clear how it could be reductively accounted for so she adopts the idea that this is a strongly emergent law of nature one that only applies to biological organisms why would you run to a particle accelerator to test that hypothesis strong emergence doesn't lead us to expect any effects at lower levels of organization and complexity so it doesn't count as any evidence against the theory that we don't see any effects at lower levels of organization and complexity if there are strongly emergent laws of nature involving for example biology then studying the microphysical world for their effects makes about as much sense as studying a rock formation it is just not a part of the theory that you would see any effects there surprisingly enough Carol seems to concede this point but you know you don't want to be radically departing or profoundly departing or dramatically overthrowing things of that nature the strong emergentist claim is not that these new causal principles which are over and above the basic laws of physics have nothing at all to say about the behavior of matter composed of protons neutrons and electrons that is not the claim the claim is that these new causal principles have nothing to say about the behavior of protons neutrons and electrons in isolation or when they are not a part of a specific higher order system or process if there are laws that only apply to macroscopic systems and processes then I'm afraid you have to observe those Mac opic phenomena there's no shortcut here the argument from the core Theory does not establish micro reductionism thank you for listening I've been Emerson green and I'll see you next time