Integrated Information Theory (IIT) is considered a promising theory of consciousness. According to IIT, a physical system is conscious if and only if it has a maximum of integrated information (“phi”).
Reading list on IIT: “Galileo’s Error” (2019) by Philip Goff, “The Feeling of Life Itself” (2019) by Christof Koch, “The Blackwell Companion to Consciousness” (2017) edited by Susan Schneider and Max Velmans. And of course the classic “Phi: A Voyage from the Brain to the Soul” (2012) by IIT’s originator Giulio Tononi. IIT is work in progress, so google recent developments.
Phi measures how strongly the parts of a physical system are irreducibly interconnected and integrated in a whole that is more than the sum of its parts, with changes in any one part making important differences to all other parts.
To find conscious maxima, integrated information must be “evaluated over all spatiotemporal scales and levels of granularities,” explains Koch. A physical system can be conscious, or it can be part of a larger conscious system, but not both. Consciousness “is present at the level at which there is the most integrated information,” explains Goff.
A molecule contained within your brain “will not be conscious, as the level of integrated information in a brain is much higher than the level of integrated information in a single molecule,” continues Goff. “However, IIT predicts that a molecule in a puddle of water will be conscious, as there is more integrated information in the molecule than in the puddle as a whole.”
This doesn’t make much sense to me. How does the molecule know if it is in a puddle of water or in your brain?
But IIT is work in progress, and it seems plausible to me that future versions of IIT could include local maxima in different scale ranges (say, Planck, molecular, human, planetary, galactic, cosmic scales), each consciously aware of different things in its own way.
Tononi seems to agree: “Exclusion does not prevent the ‘nesting’ of conscious entities over similar spatial locations, as long as there is no overlap of the cause-effect repertoires of the respective mechanisms. For example, a mitochondrion within a neuron may specify a small conceptual structure that does not causally overlap with that specified by the neuron itself together with the other neuronal elements of a complex.”
So (if my interpretation of the passage above is correct) the molecule in your brain could be conscious in its own way, aware of things like chemical or electrical phenomena at molecular scale. And you are conscious in your own way. You have maximum phi at an entirely different scale, and you are aware of entirely different things like people, politics and sports.
Similarly, the whole Earth system (call it Gaia) could be a conscious entity. The consciousness of Gaia is not excluded by and does not exclude your consciousness, because Gaia has maximum phi at an entirely different scale and is aware of entirely different things (I would like to know what).
Now extend this below molecular scale and above planetary scale and you get the idea of nested conscious systems in the universe, from the Planck scale all the way up to the cosmic scale.
This is an edited and updated excerpt from “More thoughts on consciousness and afterlife in the cosmic ocean",” posted last year in turingchurch.net.