The Divided Brain by Iain McGilchrist - my notes and summary


“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.”

“One way of looking at the difference would be to say that while 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.”

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

“The left hemisphere’s world is a representation only. It is like a map, useful precisely because almost all the information about the land to which it refers has been left out.”

“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. What do I mean by ‘betweenness’? Think about the nature of music. Music does not exist in one particular note”

“I am tempted to say it exists more in the spaces than in the notes: the spaces between successive notes in pitch that creates the melody, the spaces between simultaneously sounding notes, that is the harmony, the spaces in time between the beats, that makes the rhythm. But that too is wrong, because the spaces are just silence, apparently nothing. It is not in the spaces or the notes, but in the spaces and the notes together, plus whatever it is that comes about from their union: much as electricity isn’t in the positive pole, or the negative pole, or for that matter just in the space between them, or the sum of all those, but in the whole taken together. This is what I mean by betweenness, and it is also what mathematics consists in as much as music.”

“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.”

“Rationality, the schematic carrying out of algorithmic procedures in the way that a machine would, is better done by the left hemisphere, it is true. But other kinds of reason, including the reason that tells you the limits of reason, depends on the right hemisphere.”

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

“the origins and the end lie in the right hemisphere’s world, but it is greatly enriched by what the left hemisphere can ‘unpack’ along the way. That middle stage, of making the parts temporarily explicit, before they are once more reintegrated into the whole, is crucial.”

“The left hemisphere doesn’t realise its own limitations. Neither does logic if unassisted. It doesn’t know what it is that it doesn’t know.”

“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.”

“It is not good at understanding the world. Its attention is narrow, its vision myopic, and it can’t see how the parts fit together. It is good for only one thing – manipulating the world.”

“Its world is a representation, a virtual world, only. It neglects the incarnate nature of human beings, reducing them to the equivalent of brains in a vat. It reduces the living to the mechanical. It prioritises the procedure, without a grasp of its meaning or purpose. And it requires certainty where none can be found.”

“In the world of research, we now have to be able to say in advance what we are going to find, and no one will fund a project unless it looks like having a chance of turning up a ‘positive’ finding, which in reality means that it must be something pretty close to what we already know. We are not prepared to trust; we feel we must micro-control. The aim is to increase efficiency by avoiding what are conceptualised as waste or error, but it assures only one thing: mediocrity. Sadly many of those doing the most interesting work in any field are increasingly having to do so outside the mainstream.”

“First, it makes you powerful, and power is very seductive. Second, it offers very simple explanations, that are in their own terms convincing, because what doesn’t fit the plan is simply declared to be meaningless.”

“Third, the left hemisphere is also, as I suggest in the book, the Berlusconi of the brain – the political heavyweight that controls the media. It does the speaking, constructs the arguments in its own favour.”

“If we espouse the view of the left hemisphere we will never find meaning, because it cannot understand. It has no way to break out of the system of signs. It does not understand the power of metaphor, through which alone meaning would come about. It is not in touch. That is not its purpose, not what it evolved to help us do. It evolved to help us manipulate.”

“The left hemisphere’s world is reflexive, refers us back internally, not outwards to the embodied world. It does not care to turn its attention to the world outside the window, where, whatever it says on the piece of paper, Lieutenant Kizhe is a fraud.”

“Meaning emerges from engagement with the world, not from abstract contemplation of it.”

Written on May 23, 2024

PS: If you're interested in following my journey, sign up below: