This book by the Israeli neuroscientist Simona Ginsburg and evolutionary biologist Eva Jablonka expands on two papers of 2007 titled "The Transition to Experiencing".

The book opens with a brief discussion on teleological (goal-directed) systems and, inspired by Aristoteles, the three "modes of being", each characterized by a different telos/goal: life, sentience and rationality.

They argue that the evolution of consciousness was driven by the evolution of learning. In particular, a boost to the evolution of learning came from the "Cambrian explosion" of about 500 million years ago, when a multitude of species were created in a relatively short span of time.

Over the last few years that period has become the main suspect in the evolution of consciousness. The US neurologist Todd Feinberg and the US biologist Jon Mallatt argued that consciousness arose during the Cambrian explosion and that all vertebrates are and have always been conscious (in their 2016 book "The Ancient Origins Of Consciousness") Similarly, Peter Godfrey-Smith's book "Other Minds" (2016) identifies the "Cambrian explosion" as the trigger for the evolution of consciousness in animals that had to be more and more "aware" of other minds.

This would also mean that many more animals have consciousness than just humans. One of Darwin's youngest friends, the Canadian biologist George Romanes, already argued (in his 1883 book "Mental Evolution in Animals") that most animals must be conscious, although to a lesser degree than humans.

The book opens with a definition of consciousness as “a mode of being that involves activities that generate temporally persistent, dynamic, integrated, and embodied neurophysiological states that ascribe values to complex stimuli emanating from the external world, from the body, and from bodily actions”. It is terribly difficult to define consciousness: all definitions of consciousness leave out... consciousness. That definition can be easily implemented in a simple computer program. That doesn't mean that the computer program is now conscious.

Ginsburg and Jablonka were inspired by the Hungarian chemist Tibor Ganti, who in his book "The Principles of Life" (1971) listed the traits that characterize the minimal living being (individuation, metabolism, stability, information storage, internal regulation, growth, reproduction, and death) and worked up from that definition. Ginsburg and Jablonka suggest a similar set for the transition from nonconscious life to minimal consciousness: making information available to a plethora of cognitive processes, integrating multimodal inputs from a variety of perceptual and cognitive processes into a single percept, selection/plasticity/attention, intentionality (the ability to represent the body and the world), persistence of the integration of information over time, values/emotions/goals, and self/other distinction. That set is what they call "unlimited associative learning" (UAL), a major step forward from limited associative learning (LAL) that can only respond to simple stimuli. UAL enables an organism to assign value to experiences and use it to plan future actions as well as to predict events.

In 2020 they provided a nice table of bibliographical references: .

Ginsburg and Jablonka believe that UAL both originated during the Cambrian explosion and was one of the major driving forces causing that explosion of species. UAL exponentially increased an animal's adaptive novelty, i.e. enabled animals to develop novel behaviors that allowed them to exploit new environmental resources, to colonize new environmental niches, to become both more effective predators and more evasive prey. Unlike consciousness, which is subjective ad impossible to "measure", UAL is a tractable quantity which can be observed and measured, and related to specific brain structures and processes.

Before and after UAL there were different modes of being. And then there has been another transition in mode of being when humans evolved rationality. So they identify three modes of being: life, consciousness and rationality. This is similar to what Daniel Dennett did in "Kinds of Minds" (1998) when he identified four kinds of "creatures": Darwinian, Skinnerian, Popperian and Gregorian creatures.

They found no evidence of UAL in most animals. They found it only in most vertebrates, some arthropods (notably honey bees and fruit fies) and some cephalopod molluscs, notably the octopus. The brains of these species are anatomically different, but at the end of the day they are all capable of integrating multisensorial stimuli, of generating models of the body and of the world, of "judging" the value of situations, and of planning and predicting actions.

Why did UAL arise during the Cambrian? Implicitly they point to positive feedback: the central nervous system became more complex and caused more complex interaction and competition among animalss, which in turn caused the evolution of more complex nervous systems.

The other obvious question is what about juveniles, who are incapable of UAL until a later age, and what about machines, who are capable of UAL? Are children unconscious beings and machines conscious beings?

The authors didn't discuss how the "amount" of consciousness may have changed over the course of those 500 million years. It is implicit in their argument that it must have increased. Very few thinkers have spent time wondering whether the opposite could have happened. As i have written in my book on consciousness: "It is generally assumed that humans' ancestors had no consciousness and consciousness slowly developed over evolutionary time. Maybe it goes the other way around: consciousness has always existed, and during evolution most species have lost part of it. Being too self-aware does hurt our chances of surviving and reproducing. Maybe evolution is indirectly improving species by reducing their self-awareness."

Ginsburg and Jablonka also propose that symbolic language played a similar function for the evolutionary transition from consciousness to rationality. So they identify three transitions in goal-driven mode of being: the transition from non-life to life (the “nutritive soul”), the transition from non-conscious to conscious (the “sensitive soul”) and the transition from non-rational to rational (the “rational soul”).

The following year in their paper "Unlimited Associative Learning and the Origins of Consciousness" (2020) the authors listed testable predictions made by their theory, notably that: the five elements of UAL develop together in individuals; the five elements of UAL evolve together in species; the five elements of UAL affect each other in brain injuries.

Three years later the same authors provided an easier to read summary of their theory in the book "Picturing The Mind - Consciousness through the Lens of Evolution" (2022).

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