(Copyright © 1999 Piero Scaruffi | Legal restrictions - Termini d'uso )
The British psychologist Euan MacPhail speculates on animal consciousness, but the conclusions are as profound for human consciousness.
Macphail starts out by reviewing theories of mind from ancient times till last century, and this is probably the weakest part of the book. He claims from the beginning that philosophical theories such as world of ideas, idealism and atomism are of scarce interest today, and then delves into materialism and functionalism. This view is rapidly becoming obsolete. Quantum Theory has resurrected idealism, and no philosophical movement is in deeper disgrace than functionalism (not coincidentally, Macphail ignores the latest panpsychist theories that are often prevailing over functionalism). The world of ideas has been embraced by some of the most influential luminaries of our age.
Macphail's survey will be useful for any student of philosophy who needs a 10-minute summary of the philosophy of Hume and Kant (names that are rarely mentioned today and are rapidly fading away), but it is not very useful to focus on today's studies on cognition and consciousness. It is telling that Macphail discusses Locke (probably one of the few books on consciousness that does) but omits Berkeley, the one British philosopher who had a theory of mind, and one that is consistent with modern science. Another limit of the survey is that it covers only philosophy and psychology, whereas most of today's theories of mind have been advanced by biologists, anthropologists, physicists, etc. The interdisciplinary dimension that is so important today is somewhat missing in Macphail's book.
So much for the shortcomings. The rest of the book is an intriguing speculation on the origins of consciousness and a clever proof that animals are not conscious.
First, Macphail looks for an answer to the three fundamental questions, from an evolutionary viewpoint: when did feelings evolve? how did feelings evolve? why did feelings evolve?
There is no conclusive evidence that humans are more intelligent than other vertebrates, or, at least, no-one can express the difference in scientific terms.
Macphail notes that "association formation" is ubiquitous in vertebrates, and that it forms the basis for every form of learning.
The true difference between humans and animals is in language: humans possess an innate capacity for acquiring language. Macphail shows that humans are endowed with two parallel learning systems: a conscious (explicit) and an unconscious (implicit) system. The unconscious learning system is the human analoguous of an animal's associative learning system. Building on recent psychological studies, Macphail subscribes to the view that humans employ two memory systems, one unconscious and one conscious. While they are both present at all times, we cannot consciously recall episodes stored in unconscious memory, whereas we can consciously recall episodes stored in conscious memory. Conscious memory develops with language, and that explains why we cannot recall episodes of our early life. Other experiments show that conscious memory is an "autobiographical" memory in the sense that it develops as the concept of "self" develops. I can feel pain only after I have developed a concept of "I", only after I have come to realize that I am I. What feels the pain is the network of neurons that constitutes the self. It is Macphail's belief that language and the self co-develop in the infant.
Summarizing, the implicit memory system is common to all vertebrates and accounts for associative learning; the explicit memory system is unique to humans and requires language.
The association between a subject and a predicate in language is structurally different from the associations that animals are capable of. Animals can learn associations between stimuli, but cannot infer subject-predicates associations, and that is the prerequisite to acquiring a language. Language allows humans to think in terms of "representations", of "aboutness". Animals, who are not endowed with language, cannot grasp this "aboutness". The "aboutness" relationship is the fundamental grammatical requirement for language.
It is the capacity to deal with "aboutness" that enables the formation of a concept of self. It is the concept of self that enables consciousness. The capacity to create relationships of "aboutness" mature in children and leads to a conception of the "non-self", which in turns is reflected in a conception of the "self". At this point conscious memory starts developing, and conscious recall is possible, and conscious life begins. Consciousness is the consequence of the evolution of "aboutness".
Inasmuch as "aboutness" is the key to consciousness, Brentano was therefore correct: intentionality is the fundamental property of mind, that distinguishes it from matter.
Macphail's skills as a writer are impressive. He unveils the solution of the puzzle like a mystery writer who is searching for a "whodunit". His logical proof takes slowly, shape chapter after chapter, like the lengthy demonstration of a mathematical theorem.
What rests to be explain is what causes infants to diverge from other animals. If, as toddlers, we are no more conscious than puppies, what happens to toddlers than does not happen to cubs, so that after a few years a toddler is conscious and a cub will never be? Ultimately, Macphail postulates that the answer lies in our ability to learn languages. There is something in our genetic repertory that sets in motion the process to learn languages.