There was a tremendous seminar on Iain McGilchrist's book, The Master and His Emissary, yesterday at the RSA. (There are plans to publish a summary of the discussion pretty soon.) The two key aims were to test the thesis and to ask what difference it makes.

The thesis might be broken down into two parts. First, that work on the two hemispheres of the brain suggests we have broadly two ways of attending to the world, and so rooting our values too, and that things go best when we have access to the two ways, which is to say that there is a synthesis of both, rather than the denigration of one by the other.

Second, McGilchrist contends that we live in a world enamoured with a way of looking at the world that over-values the attention associated with the left hemisphere - roughly, attention that is focused and manipulating; and under-valuing open and connecting attention.

I'd say that most people in the seminar could go along with the first part, particularly when it is remembered that McGilchrist stresses that (a) his thesis is not that the brain causes anything but that it constrains attention - much as land does not cause water to flow but constraints its flow; and (b) that all the ramifications of his thesis can be arrived at by other ways, it is just that neuroscience provides a particularly powerful discourse for discussing them.

When it comes to the difference it makes, for myself the book brings three thoughts sharply to my mind. The first is about how we do ethics.

Two approaches have dominated in the modern world - utilitarian ethics, which focuses on the attempt to measure and maximise things like happiness; and deontological ethics, which focuses on the attempt to reason out what we should and shouldn't do. These might be the preferred approaches one would expect in world that trusts the human capacities McGilchrist associates with the left hemisphere. But there are all sorts of reasons for believing that they are now not serving us well - and they also sideline and misunderstand a third tradition that it seems possible to associate more with the capacities associated with right hemisphere functioning. This is virtue ethics. Virtue ethics takes the ups and downs of life as the basic stuff of ethics and cultivates the ability to reflect upon experience so as to learn from mistakes, tolerate the uncertainties of living, nurture the habits that enable one to flourish, and over time gain a feel for how to live well - that lived sense of understanding we might call practical wisdom.

The second thought is not unrelated and has to do with McGilchrist's central thesis that the way the hemispheres function constrains how we perceive the world. If it is right that we have broadly two ways of attending to life, one focused and directive, the other open and connecting - and this seems right to me as it is something that has been repeatedly observed by adepts in spiritual traditions - then it will presumably also be the case that we can nurture our attention so as to develop different perceptions of and approaches to life. It will no doubt be a difficult even painful task to cultivate a way of attending that does not come naturally in the modern world, that is to cultivate the open and connecting in a milieu that prefers the focused and directive. But it seems pretty clear that having access to both kinds of attention is crucial.

The third thought is related again, and concerns having a capacity for uncertainty - an ability to stay with the anxieties of doubt and not reach out after faux-certainities; as well as an ability to resist the temptation to need to be doing something, anything, and/or unconsciously seeking escape in distractions. The psychotherapist Donald Winnicott called it 'going on being', arguing that trusting life itself rather than the nervy isolated self, is fundamental if creative and unexpected insights are to unfold. Again, this would seem to be a far more difficult state to sustain when the capacities associated with the right hemisphere are lost or denigrated.