On reading Will Durant’s book, The Story of Philosophy, I realised that for years I had understood Rene Descartes’ famous quote wrong. Cogito, ergo sum, translated to English as ‘I think, therefore I am.’ I thought it implied causality! To me, Descartes was saying that I think, and as a result I am. In fact, what Descartes meant was that I think, thus I can infer that I am. He was not trying to tell us why we existed, he was simply giving us direct proof of our existence. Realising this caused me much embarrassment, because
I used to proudly flip the statement around and display status messages that said- I am, therefore I think. Sum, ergo cogito. Of course, what I meant was that I am, and as a result I think!
Descartes’ proposition is a fundamental element of philosophy, a direct proof for the existence of the self. Even if you doubt it, the very fact that you doubt is proof that you exist. In other words, there must be a thinking entity for there to be a thought, so any thought is automatically evidence of a thinking entity. But what is a thinking entity, and how does one differ from another? Can animals be thinking entities too? Are a thinking entity and a biological entity completely intertwined, where the former cannot exist in any form beyond the latter? Does the laddered view of reality place consciousness in the correct order? The psychologist William James used Descartes-like logic to say that consciousness needed no operational definition, since all of us are familiar with it through introspection. Like in the previous chapter, we will view the matter through the three filters of theology, science and psychedelic speculation. But first, it’s best we begin with the question of when did human consciousness arise.
More than an Ape
In his book Incognito, neuroscientist David Eagleman likens our consciousness to the CEO of a large firm. Most day-to-day activities happen below the CEO’s level of awareness, and she is called in when there is a crisis or when there is need of long term planning. Eagleman gives us the example of activities such as driving, where once our brain is habituated with the process, most of it can take place below our ordinary level of awareness. In fact, for most things we want to excel at, it’s best to ingrain the motions so that we do not need to think of them consciously. Think of how we internalise typing or playing the piano, and you’ll know what Eagleman is trying to say. Approaching it from the lens of physics and information computing, Max Tegmark calls consciousness the way information feels when being processed in highly complex ways. Both would agree with the laddered view, which sees consciousness as a result of evolutionary processes.
But how does the timeline of such an evolution look? When and how did evolution draw such wide changes between human and chimpanzee self-awareness? In this book, we avoid the debate on whether humans are ‘merely another ape’ or ‘something special in the universe.’ If we weren’t human, we would scarcely care. But since both you and I are humans, any comprehensive discussion must also discuss our unique traits, for human intelligence possesses a wider range of creativity and flexibility than any other animal. Science agrees that this has something to do with our uniquely large brains.
Along with the other apes, humans are part of a family called the primates, which evolved from a shrew-like ancestor that managed to survive whatever killed the dinosaurs. Early primate life involved living in groups, which meant that every member had to navigate a complex web of relationships. This happened 30 to 60 million years ago and is one of the first things that drove an increase in brainpower. 10 to 15 million years ago, the ape line split from other primates, and this is where we would find the ancestor we share with chimpanzees, gorillas and orangutans. Biologists have identified a gene in this ancestor which could have boosted the flow of blood to the brain by widening the carotid artery- the one that supplies your head and neck with oxygenated blood.
Around 7 million years ago we find the ancestor we share with chimpanzees, who are our closest living relatives. Early hominid and chimp-like lines would have looked similar, but again biologists have identified certain genes in humans that could have been responsible for growth in the cerebral cortex- which plays a role in a wide variety of functions such as memory, perception, language and consciousness. Other gene mutations could have tweaked glucose flow away from the muscles and towards the brains, allowing them to grow bigger. Yet another set of mutations work on dexterity, allowing hominids to make complicated stone tools and later, write words. This in turn was facilitated by the fact that our ancestors began walking on two limbs. Our jaws weakened over this period compared to chimp jaws, which could have freed up further space for our brains to grow. Lastly, when our ancestors turned omnivorous, the additional sources of protein further propelled growth in brain size.
These apes with enlarged brains evolved, some 3 million years ago, into the homo genus. It is not settled which human species was first, but consensus seems to favour homo habilis. A crucial mutation occurred before the Neanderthals arrived on the scene. All great apes have air sacs in their vocal tracts that allow them to make loud bellows. This makes it impossible to produce different vowel and consonant sounds, thereby precluding them from speech. Humans don’t have these air sacs, and evidence suggests that our ancestors lost them before homo sapiens and Neanderthals diverged. This means that the Neanderthals possibly had language just like us and has important implications for the sort of consciousness we are trying to find. We have even found a gene called FOXP2, which is crucial in the grasp of grammar and pronunciation. Neanderthal FOXP2 looks just like ours, but scientists are divided over whether this means that Neanderthals had language too.
It is important to understand that the story of human evolution has been developed over several decades with much debate and controversy, and it is not yet complete. The account given above represents the broad narrative and does not confess the points of conflict among modern biologists. For example, it wasn’t always understood that homo sapiens originated from Africa, and even now the question of how and when we replaced other human species isn’t neatly settled. New discoveries continually change our understanding and challenge the ‘out-of-Africa’ hypothesis and its timeline.
Along with other human species such as homo rhodesiensis and homo heidelbergensis, Neanderthals are grouped in a broad category called archaic humans which evolved around 500,000 years ago. Anatomically modern humans, homo sapiens, evolved 200,000 years ago. There are further divisions between homo sapiens sapiens (us) and homo sapiens idaltu (‘the elders’). For more than 100,000 years, several human species co-inhabited this planet. Indeed, some evidence suggests that there were possibly a few successful cases of cross-breeding as well. As Yuval Noah Harari says in his book Sapiens, the idea that we could at some point in time have had intercourse with only a marginally different species is both unsettling and thrilling.
Viewing evolution through the ‘anthropic principle’ makes us see natural selection as a process with homo sapiens at the pinnacle. But in purely physical terms we are nowhere as ‘perfected’ as a big cat in its natural habitat. What sets us apart is our brain, which lends to us a remarkable ability to innovate and adapt in ways other species simply do not. Neither should we see the evolution of humanity as a step-by-step process where homo habilis lead to the Neanderthals, who in turn led to us. Indeed, if brain size is any indicator then we should note that the Neanderthal brain was larger than the homo sapien brain.
While there are conflicting theories on how it happened, by around 10,000 to 15,000 years ago homo sapiens were the only human species left on the planet. All our cousins went the way of extinction, and it is quite possible that we are guilty of fratricide on a massive scale. If homo sapien history is any indication, our xenophobic past should come as no surprise. In the previous chapter, I mentioned how the power of language has helped us deem other groups of humans as sub-human or non-human. If we possessed language when we co-inhabited the planet with other human species, I wonder how we looked upon them (or vice versa.) Enthusiasts might attempt here to find parallels between different human species and the landscape of hominid creatures in Hindu mythology- Vanaras, Kimpurushas, Kinnars, Danavas, Daityas, Asuras, Devas and so on. Such landscapes exist in other traditions as well, and we can indeed speculate whether they reflect a racial memory of not being the ‘only ones’ at some point in history.
It is in the context of this timeline that we are faced with the task of identifying when modern human consciousness arose. The definition of evolution as a gradual process that works over millions of years suggests that consciousness too emerged as an incremental ability over generations, as does Eagleman’s CEO-analogy. To justify this, we need to be able to identify the evolutionary benefits of possessing self-awareness of the kind we do. This is provided by observing that primate, ape and human life increasingly demanded handling complex social and physical situations, including the nurturing of infants. The CEO-analogy explains this by comparing a small-firm to a large-firm. A small-firm can exist even without a CEO, with the interaction between constituent parts running the ship satisfactorily. As the firm grows, with more employees adding more complexity and inter-connections, a decisive and empowered leader at the top becomes necessary. A similar sort of change might have occurred in human life as our ancestors learned to create new tools, control fire and live in complex social groups.
One might argue that other apes live in highly complex social groups as well, and there are clear hierarchies with an alpha male at the top driving decisions and long-term planning. But there were critical differences in the lives of early humans and other apes, largest of which was the increasing brain size. When our ancestors left their jungle habitats and began walking on two legs, they became more vulnerable to predators such as big cats. Increased vulnerability would have imposed increased evolutionary pressures that naturally selected for smarter decision making and innovative escape making. The same applies for when they started hunting big game like mammoth, caribou and bison. Bear in mind that all these changes worked over a period of a few million years, and after humans evolved the changes would have varied between different human species. Taken together, these human species were evolving through adapting to an increasingly large geographical sphere. In contrast, chimpanzees never left Africa until modern humans exported them elsewhere for zoos and laboratories.
But even as we feel confident that we are the only species on the planet today with a higher order of self-awareness, can we be certain that this was so in the past as well? If consciousness has originated through the physical and social changes taking place in human lives, could it have originated in Neanderthals as well? Or in the Java Man? Or Homo Habilis? Could we point to a specific moment in time, before which there was no consciousness and after which there was? This takes us back to the generation-wise journey we made to the common ancestor we share with chimpanzees. It suggests that we are unlikely to find any specific moment in time which was the origin of consciousness. Consciousness is quite obviously a spectrum with unicellular organisms at one end and homo sapiens at the other. At our end of things, the differentiating factors begin with language and culture.
We thus go back to the situation imagined at the beginning of this book. When homo sapiens began painting the walls of ancient caves, is that our first hint of the emergence of higher order self-awareness? Can we take symbolism and meaning as evidence of consciousness? If yes, we must note that Neanderthals are speculated to have had language as well, used fire, hunted big game meat, made advanced tools, lived in complex social groups and had burial rituals. This means that even human consciousness is not unique to us, and that the metaphor of a universe becoming self-aware can no longer place us at the centre. But this is a speculative realm where anthropologists, biologists and archaeologists are not in complete agreement. What everyone can agree though, is that what separates homo sapiens from other extant species is the ability to come up with something like cogito, ergo sum. While we have no quarrels on whether cats, dogs, dolphins and many other animals possess a complex order of awareness, we do not think they are capable of the sort of high thinking and reasoning we are so good at. Let us now see how we have defined and understood this sort of high thinking through the ages.