I have read the latest publications from the groups developing the Assembly Theory (AT) and the Integrated Information Theory (IIT). I am not qualified to critique these theories, but I wanted to say few words about them because I see similarities between AT and IIT.
AT and IIT emphasize axiomatic, recursive, and operational explanations with strong emphasis on path-dependence.
Recursive, axiomatic, operational
Recursive explanations involve feed-back loops referring to self (life in the case of AT, consciousness in the case of IIT).
In AT and IIT, life/consciousness is the axiom – the starting point. AT assigns primary ontological status to “life”, IIT to “consciousness” and investigate what must have happened in the past for life/consciousness to emerge. These theories place more emphasis on the operations/functions on the substrate rather than the substrate itself.
Teleological?
The basic logic of AT and IIT – starting from life/consciousness and going backward – sounds teleological. I have no problem with teleological explanations, but this is one of many criticisms AT/IIT will face.
Path dependence
Both AT and IIT put a lot of emphasis on path-dependence. Standard theories of science emphasize the laws (equations, regularities, mechanics, dynamics). AT and IT say that “history” (the specific path taken) is more important than the laws. The specific path (individual history) taken in the course of evolution eliminates countless number of other possibilities and selects for a narrower space of future possibilities.
AT and IIT do not deny the dynamical laws, but they do not assign primary importance to them. They seem to pay attention to the conservation laws (constraints), however. Otherwise, they could not explain the evolutionary selection – the elimination of future possibilities based on the specific path taken.
Causal closure of the physical
The axiomatic approach may give you the impression that AT and IIT are trying to go beyond the physicalist paradigm. On the contrary, I think that both AT and IIT try to achieve the “causal closure of the physical“. In other words, they both try to achieve the physicalist ideal of explaining life/consciousness in physical terms. AT and IIT expand the definition of “physical” by including operations/functions in the definition.
In AT and IIT the explanatory factors are functions/operations rather than the building blocks themselves. For example, in this view, life/consciousness can be based on carbon or on any other chemical or electronic substrate as long as the functions/operations result in life/consciousness.
Similarities to Howard H. Pattee’s theory
Please see my post titled “Semiotic Closure” to compare AT and IIT to Howard H. Pattee’s theory. There are some similarities in the usage of self-reference, but there are clear differences as well. Pattee separates explanatory factors into rate-dependent and rate-independent (symbolic) categories and investigates the interplay between these categories. I don’t see this kind of categoric separation in AT/IIT. Another difference is the AT/IIT emphasis on path-dependence. I don’t see much emphasis on path-dependence in Pattee’s theory.
Operational explanations
IIT/AT emphasis on functions/operations rather than the underlying substrate doesn’t sound strange to physicist ears. In Quantum Mechanics and Quantum Field Theory “operators” are primary.
Operations/functions can be thought of as mathematical maps. The mathematical map does not have to depend on time. But in IIT/AT, most explanatory factors seem to be time-dependent functions.
Placing emphasis on mathematical maps (operations/functions) has merits. The substrate cannot be ignored, however. Operations/functions or maps in general act on the substrate/field. We can also say that functions/operations activate the substance and facilitate the appearance of attributes.
AT and IIT assume that the substrate is physical. There are levels of physicality. In my opinion, the substrate at the subtlest level of physicality is the primordial fabric which is a stage in the transformations of life/consciousness. There must be realms even subtler than the primordial fabric, but those realms are beyond the scope of science.
Integrated Information Theory
IIT was proposed by neuroscientist Giulio Tononi in 2004-2014 [1]. The latest form of IIT was published as a PLOS article on October 19, 2023 [2].
“It must be emphasized that taking the phenomenology of consciousness as primary, and asking how it can be implemented by physical mechanisms, is the opposite of the approach usually taken in neuroscience: start from neural mechanisms in the brain, and ask under what conditions they give rise to consciousness, as assessed by behavioral reports. While identifying the ‘‘neural correlates of consciousness’’ is undoubtedly important, it is hard to see how it could ever lead to a satisfactory explanation of what consciousness is and how it comes about.” [1]
“IIT’s starting point is experience itself rather than its behavioral, functional, or neural correlates. Furthermore, in IIT “physical” is meant in a strictly operational sense—in terms of what can be observed and manipulated.” [2]
“The physical account of consciousness provided by IIT should be understood as an explanatory identity: every property of an experience should ultimately be accounted for by a property of the cause–effect structure specified by a substrate that satisfies its postulates, with no additional ingredients. The identity is not between two different substances or realms—the phenomenal and the physical—but between intrinsic (subjective) existence and extrinsic (objective) existence. Intrinsic existence is immediate and irrefutable, while extrinsic existence is defined operationally as cause–effect power discovered through observation and manipulation. The primacy of intrinsic existence (of experience) in IIT contrasts with standard attempts at accounting for consciousness as something “generated by” or “emerging from” a substrate constituted of matter and energy and following physical laws.” [2]
“…according to IIT feed-forward systems cannot give rise to a quale. However, without restrictions on the number of nodes, feed-forward networks with multiple layers can in principle approximate almost any given function to an arbitrary (but finite) degree. Therefore, it is conceivable that an unconscious system could show the same input-output behavior as a ‘‘conscious’’ system.” [1]
Assembly Theory
The Nature article published on October 23, 2023, titled “Assembly theory explains and quantifies selection and evolution” [3] attracted a lot of attention. Lead authors are Leroy Cronin and Sara I. Walker.
The motivation behind AT was the desire to detect evidence of life on other planets or moons from data gathered by astronomical observations.
A popular exposition of the Assembly Theory (AT) was written by Philip Ball in a Quanta article titled “A New Idea for How to Assemble Life“. Few quotes from Philip Ball’s article.
“In accounting for specific, actual entities like humans in general (and you and me in particular), traditional physics is only of so much use. It provides the laws of nature, and assumes that specific outcomes are the result of specific initial conditions. In this view, we must have been somehow encoded in the first moments of the universe. But it surely requires extremely fine-tuned initial conditions to make Homo sapiens (let alone you) inevitable.
Assembly theory, its advocates say, escapes from that kind of overdetermined picture. Here, the initial conditions don’t matter much. Rather, the information needed to make specific objects like us wasn’t there at the outset but accumulates in the unfolding process of cosmic evolution — it frees us from having to place all that responsibility on an impossibly fine-tuned Big Bang. The information “is in the path,” Walker said, “not the initial conditions.” “
References
[1] Oizumi M, Albantakis L, Tononi G (2014). “From the Phenomenology to the Mechanisms of Consciousness: Integrated Information Theory 3.0 “, PLoS Comput Biol 10(5): e1003588. doi:10.1371/journal.pcbi.1003588
[2] Albantakis, Larissa et al. “Integrated information theory (IIT) 4.0: Formulating the properties of phenomenal existence in physical terms”. PLOS Computational Biology. 19 (10): e1011465. doi:10.1371/journal.pcbi.1011465. PMC 10581496. PMID 37847724.
[3] Abhishek Sharma, Dániel Czégel, Michael Lachmann, Christopher P. Kempes, Sara I. Walker, Leroy Cronin. Assembly theory explains and quantifies selection and evolution. Nature 622, 321–328 (2023). https://doi.org/10.1038/s41586-023-06600-9
L.C. and S.I.W. conceived the theoretical framework building on the concept of the theory. A.S. and D.C. developed the mathematical basis for the framework and explored the assembly equation, and A.S. did the simulations with input from D.C. M.L. and C.P.K. helped with the development of the fundamentals of assembly theory. L.C. and S.I.W. wrote the manuscript with input from all the authors.
Suresh Emre
Renaissance Universal 