The Divided Brain and the Search for Meaning

by Iain McGilchrist

we are nothing but blind mechanisms, the dupes of our equally blind genes, with no choice but to play out the sorry farce that the force of evolution, so much bigger and greater than we are, dictates. But at least now we have the dignity of knowing that we are not deceiving ourselves.

we can only know the world as we have inevitably shaped it by the nature of our attention.

than a hundred years physicists have understood that matter is not separable from consciousness. The mechanical universe is dead, in both senses.

We make the world we live in by attending to it in a certain way, by our disposition towards it.

What we do not expect to find, we just will not see: much elegant research demonstrates that we are essentially blind to what we do not think is there.

What we call our consciousness moves back and forth between them seamlessly, drawing on each as required, and often very rapidly.

it is the left hemisphere that controls the right hand with which we grasp something, and controls the aspects of language (not all language) by virtue of which we say we have ‘grasped’ the meaning – made it certain and pinned it down. The right hemisphere underwrites sustained attention and vigilance for whatever may be, without preconception. Its attention is not in the service of manipulation, but in the service of connection, exploration and relation.

the left hemisphere's raison d'être is to narrow things down to a certainty, the right hemisphere's is to open them up into possibility.

all thinking, most obviously philosophical and scientific thinking, is at bottom metaphorical in nature, though we are so familiar with the metaphors that we don't notice their existence.

Explicitness kills, renders lifeless.

the left hemisphere's world as tending towards fixity, whereas that of the right tends towards flow. All systems in nature, from particles to the greater universe, from the world of cellular processes to that of all living things, depend on a necessary balance of the forces for stasis with the forces for flow. All existing things could be thought of as the product of this fruitful tension.

The left hemisphere's take on things comes from assessing thousands of points of information in turn and trying to reach a conclusion about the whole picture that way.

the right hemisphere, which sees things as a whole,

the purpose of the left hemisphere is to allow us to manipulate the world, not to understand it.

The right hemisphere seems to be involved more with new experience, new events, things, ideas, words, skills or music, or whatever it may be, while they are still fresh, original and unique, and so to speak present, to the mind. The right hemisphere's world is present – or more precisely ‘presences’ to us, as Heidegger puts it. By contrast the left hemisphere's world takes over once whatever it is is represented – literally ‘re-presented’ after the fact: once it is familiar and known, as an instance of something, a concept.

following a left hemisphere stroke, the right hemisphere delivers a complete world, not a half-world.

The left hemisphere is not in touch with reality but with its representation of reality, which turns out to be a remarkably self-enclosed, self-referring system of tokens. I'd say the defining quality of the right hemisphere's world is that it is all in relations, what I call ‘betweenness’. This starts with its having a relationship with the world at large, not seeing it as a separate object, ripe for manipulation.

The left hemisphere is especially good at voluntary and social expressions of emotion and one of the most clearly lateralised emotional registers is that of anger, which lateralises to the left hemisphere. Deeper and more complex expressions of emotion, and the reading of faces, are best dealt with, however, by the right hemisphere. As far as reason goes, the left hemisphere is better at carrying out certain procedures that involve manipulating numbers, but has less of a grasp than the right hemisphere of what those numbers mean. Much of mathematics is dependent on the right hemisphere: most of its great discoveries were perceived as complex patterns of relationships, and only later, often much later, translated painstakingly into linear sets of propositions. Deductive logic, it turns out, depends on the right hemisphere.

when our theories about the world, our ways of thinking, come face to face with reality and show themselves to be inadequate to understanding the world.

‘Ship of Theseus’ paradox, also known as the ‘Growing Paradox’, because it arises in the case of all living things. It goes like this: the ship in which Theseus returned to Athens from his exploits in Crete was preserved there in the harbour as a memorial. With time the timbers perished one by one and were replaced, so that after thirty years none of the original timbers remained. Was this still the Ship of Theseus? This is an analogue of the problem that few of the cells in my body were there a year ago – so is it still my body? To anyone seeing the whole, and who realises that everything flows, the answer is clearly ‘yes’.

the left hemisphere sees truth as internal coherence of the system, not correspondence with the reality we experience.

concepts without intuitions are empty, intuitions without concepts are blind. We need the contributions of both, but for different purposes. An uncritical following of intuition can lead us astray, but so can an uncritical following of logic. The reasoning of those who have spent their lives attending wisely to their intuitions is better than that of those who have never done so, and the intuitions of someone who has spent a life attending to reason will be better than those of someone who has not.

the right hemisphere is perfectly happy with ‘both/and’ – sees in fact how necessary that is in understanding the world. The left hemisphere, by contrast, says: ‘What's the matter? Can't you make up your mind?’ It has to be ‘either/or’, black or white, never a life within the full colour spectrum.

Of the two, one is of greater importance when it comes, not to manipulating the world, but to understanding it, and living in it, and with it. The right hemisphere, the so-called minor hemisphere, is in fact the one that knows, and more importantly the one that understands, more.

Most people are completely and unreflectively seduced by the rhetoric of reason. And incidentally, some recent influential work in evolutionary theory suggests that this may be the whole purpose of logic – not to understand, but to persuade, to seduce, others and win a competitive argument.

Is it logical to rule out the possibility, understood for millennia, that there was a difference between the sort of knowledge that is available to logos and the sort that is available to mythos? Is it logical, or an assertion of faith, to assign reality to only one of these kinds of knowledge? Is it logical, or just a dogma, to assume that all will be understood, as long as we only carry on applying the model of the machine?

The left hemisphere is not in touch with the world. It is demonstrably self-deceiving, and confabulates – makes up a story, when it cannot understand something, and tells it with conviction.