These two kinds of attention came about for an evolutionarily important reason. Every creature has to solve this conundrum: how can I eat and yet stay alive? That doesn’t sound difficult, but if you think back: for most of history, a creature has to be able to target something, follow it with its eyes, and get it very accurately. To do that it has to have very narrow attention. But if that’s the only attention it is paying, it won’t last very long, because he won’t see the predator overhead, it won’t see its mate and its offspring that also need feeding. So there needs to be two kinds of attention, and so different are these kinds of attention that they can only come about by having two centres of awareness.

The left hemisphere has a very narrow beam, targeted on a detail which it can see very precisely. It fixes it and grabs it (and the left hemisphere controls the right hand with which most of us do the grabbing and the getting). Whereas the right hemisphere has a broad, open, sustained vigilant attention, which is on the lookout for everything else without preconception. So on the one hand you’ve got an attention that produces a world of tiny fragments that don’t seem connected to one another — a bit here a bit there, a bit elsewhere — that are decontextualised, disembodied. Whereas with the right hemisphere we see that nothing really is completely separated from anything else — that ultimately, all this is on some level seamlessly interconnected, that it’s flowing and changing rather than fixed and static. Uniqueness is something the right hemisphere sees, while the left hemisphere sees just an example of something that it uses or needs. The right hemisphere is the world in which we live; the left hemisphere’s world is, if you like, a map, a schema, a diagram, a theory — something two dimensional. So we’ve got this one world, which is composed of things that are mechanical, useful, inanimate, reducible to their parts, abstracted, decontextualised, dead; and another world, which is flowing, complex, living, changing and has all the qualities that make life worth living.