Robert Graves popularised the modern idea of the poet's Muse, suggesting its divine inspiration was manifested in certain women "in whom the goddess is to some degree resident". Whilst contemporary poets might not always see the Muse in Graves' terms ('Er, Bob, meet Karen, my Muse'), the notion that poems come to us from 'elsewhere' still holds firm. According to Nuala Ni Dhomhnaill, "a poem is a smuggling of something back from the otherworld, a prime bit of shoplifting where you get something out the door before the buzzer goes off." Elsewhere, Stephen Dobyns has suggested that "writing poems is like waiting for lightening to strike". Whether our metaphors for inspiration draw on the underworld or the heavens, the idea that the best poems come unbidden is familiar to most poets. You can hear Ted Hughes talking about the strange arrival of his poem 'The Thought Fox' here.
'The Origin of Consciousness in the Breakdown of the Bicameral Mind' suggests that Muses and the art of poetry itself are partly explained by the evolution of the human brain. His discursive exploration of what consciousness is (or, more intriguingly, what it isn't) offers the startling suggestion that human beings were not in fact 'conscious' (in the sense of having an analog sense of 'I' and 'me' and narratizing experience) until between 700 and 900 BC.
'bicameral mind' with two unconscious halves, one symbolising man (the follower) and one symbolising God (the executive). Auditory hallucinations, believed to be from the Gods, told people what to do and imposed an order. In other words, one half of the brain 'spoke' while the other listened and obeyed. Later on, geological, social and economic changes created pressures that led to the bicameral mind developing the facets we now associate with consciousness (here, you'll have to forgive me for summarising an argument that Jaynes builds painstakingly, in great historical detail, since it's the concept of the bicameral mind that interests me rather than its later evolution). Suffice to say, the brain's inherent plasticity enabled it to evolve to meet the new needs of civilisation. The shift from the bicameral mind to consciousness is reflected, Jaynes believes, in the 'Iliad': whilst "the earliest writing of men in a language that we can really comprehend...reveals a very different mentality from our own", later additions to the 'Iliad' show signs of something more akin to modern, subjective consciousness.
This duality of ancient mentality is represented, Jaynes argues, in the duality of the cerebral hemispheres and the functional asymmetry of the brain: a different, if not entirely contradictory account of the brain's historical duality can be found in Iain McGilchrist's 'The Master and his Emissary', of course. Some of the holistic guiding and planning functions of the right hemipshere echo the function of God in the bicameral mind. Discussing the left hemisphere's specialisation in some structural, literal aspects of language, Jaynes suggests "the language of man was involved with only one hemisphere in order to leave the other free for the language of the Gods". He is over-simplifying his case here - both hemispheres have important, complimentary roles in language comprehension and production (see writers such as Hellige if you want an excruciating level of detail) - but as a metaphor, it's fascinating.
Most crucially for our purposes, Jaynes believes that the evolution and decline of the bicameral mind is intrinsically linked with the nature of poetry. Poetry, Jaynes argues, began as a form of incantatory, divine knowledge, "the language of the Gods". The "association of rhythmical or repetitively patterned utterance with supernatural knowledge" gave poetry the ability to command where prose could only ask. Speech is primarily of the left hemisphere (or the domain of man), but song is of the right hemisphere (or the realm of the gods and auditory hallucination): strikingly, patients with left hemisphere damage who have lost the ability to speak often retain the ability to sing. Thus poetry, with its origins in song, retains something of that early, hallucinatory quality, even though it has since become a hybrid form with "the metrical feet of song and the pitch glissandes of speech", its evolution from incantation to more conscious recitation mirroring the breakdown of the bicameral mind.
Milton, Rilke and, of course, Blake are part of this bicameral aspect.
Writing about 'The Asylum Dance' in a piece quoted in the prose collection 'Don't Ask Me What I Mean', John Burnside said: "if anything could have served, for me, as a reminder that poetry is a shared practice, ...inspired by the pauses in conversation and the sounds and silences of habitat, it was the writing of this book, where so much arose from the relationship between the making of a poem and the act of listening, not only to other humans, but - in a hopelessly clumsy way - to the land and the water and the air." It seems only appropriate, then, to end with his poem 'The Inner Ear':
It never switches off; even asleep
we listen in to gravity itself.
Crossing a field is one long exercise
in equilibrium - a player's grace -
though what we mean by that
has more to do
than the physics we imagine.
A history of forest and the murk
of oceans, nice
in the memory of bone
lead us to this: the gaze;
the upright form
Lemur and tree-shrew linger in the spine
becoming steps: a track worn in the grass
a moment's pause
before the rain moves in.