The right hemisphere generates attention that is, for want of a better word, holistic. It sees in terms of the whole, and of the quality of the whole. The shape and the flavour of things.
To give you a sense of the difference between concepts (left hemisphere) and quality (right hemisphere), think of, say, the colour red. Try to describe the colour red in words, and you will very rapidly find yourself stuck. It's just not the kind of thing that you can really put into words — but that's not to say that it's in any sense a vague thing.
Colour is very specific, and so is shape. Now with shape, you can of course talk in terms of simple geometry, of triangles and square, circles and cones. But reality is rough, to paraphrase the father of fractal geometry, Benoit Mandelbrot. The closer you look at anything real, the less simple it seems, the more roughness becomes apparent.
The natural world is full of examples — something simple, like a tree, isn't a very simple shape at all. Try to describe the shape of a tree in a way that communicates any real level of what that shape actually is, and you'll find yourself running into the same problem as you just did with the colour red.
Nonetheless, if you look at a tree, there it is, there the shape of it is.
That image of a tree is something that your brain creates from all the sense data that's coming in. And so in one sense, actually, your brain is very much able to accurately describe the complexity of its shape. That's what the image is. And yet, somehow, you can't.
You can't describe the shape of a tree, but your brain can. A strange divergence, and one that should make more sense by the end of this piece.
That's the difference between left-hemisphere and right-hemisphere thinking. The right hemisphere is more than happy — and more than able — to represent a unique quality, or a complex shape. The left hemisphere is not happy — and not able — to describe either.
Contour and quality are the domains of the right hemisphere. The kind of attention it generates is, in McGilchrist's own words, non-dual. Flavour, colour, quality. Not some abstracted concept, but the actual fullness of reality as such — the specific, particular, and indescribable contour of what is actually happening.
Right hemisphere thinking is far more comfortable with uncertainty about absolute rules. In fact, it doesn't really care about certainty at all, because it doesn't really care about rules. It's not building categories to lump things together — it's seeing the whole of things, and relating them as honestly and accurately as possible. It is the link between humanity and reality.
This brings us to a very interesting aspect of right-hemisphere attention — it is all about experience. All about what's actually going on, right now. What is essentially happening.
The right hemisphere doesn't trade in certainty, or division. It trades in the qualities of things, the specific contour of the real. And whereof we cannot speak, it has seas and oceans of things to say.