I had been watching the Franz Kafka lookalike since we left Paddington. The train was full but the seat next to him remained unoccupied. The woman had lasted ten minutes, the man about five. He seemed oblivious to both. I could see him mouthing something but his voice was hard to discern against the hubbub of conversation and the ambient clatter of the track. I listened closely. Other solitary passengers sat quietly reading or staring out the window but this man was deep in conversation with himself. I assumed he was psychotic and at war with his voices. But his tone was relaxed. I'd say he was in good spirits. Even so, he was making people uncomfortable. I registered a hostile glance or two. Why? He didn't seem to be saying anything offensive. He was only making public what the rest of us keep private and I was intrigued to be dipping into someone else's stream of consciousness. We all have a little inner voice, but to talk aloud to oneself in the presence of others is to breach a surprisingly rigid social code. I wondered if I had the nerve to start talking to myself and realised I didn't.
I'm not much of a self-talker. Occasional words of admonishment slip out ("Idiot!") or frustration ("Oh, come on!") or celebration ("Yes!"), but I don't indulge in soliloquy. Still, that little inner voice plagues me to death when I sit down to write. Faced with a blank screen or notepad, the subterranean babbling brook of words bubbles almost, though never quite, to the surface. I can vaguely hear it. In fact the whole process of writing is akin to talking to oneself. Words pour forth with no interlocutor in sight. The person we are addressing is absent, or our words are intended for no one in particular - some imaginary, generic "reader." And the point of writing, of course, is to take charge of the little voice in someone else's head, whether fleetingly or over the long, absorbed hours required to read a novel. Readers happily relinquish control. It feels natural and satisfying to submit to the guidance of another voice and have someone else take charge of one's thoughts. So perhaps the American psychologist Julian Jaynes was really on to something with his much disputed (detractors say crackpot) account of the history of consciousness, in which he claimed that it is only recently - since the 2nd millennium BC - that human beings have felt themselves to be the authors of their own thoughts and actions. Prior to that, behaviour was directed by hallucinated voices perceived to be of external, supernatural origin (although actually arising from the right hemisphere of the brain). "There is in general no consciousness in the Iliad" says Jaynes in support of his thesis, "And in general therefore, no words for consciousness or mental acts." Achilles and Agamemnon were, effectively, automata - puppets of the gods. To lose oneself in a book, to be beguiled and steered by the authority of another voice, is almost to enter a comparable state of hallucination. According to Jaynes, the "bicameral" mind of our proto-conscious ancestors reflected a greater functional separation of the brain's hemispheres. That we are now autonomous and introspective is not due to changes in the brain's hardware but rather to software developments wrought by social and cultural change. But vestiges of premodern mentality abound. They are evident, for example, in the universal appetite for religious authority and ritual. ("When did I realise I was God?" says Peter O'Toole's character in The Ruling Class, "Well, I was praying and I suddenly realised I was talking to myself.") Hypnotism and the auditory hallucinations associated with schizophrenia are other examples cited by Jaynes. Much of his psycho-archaeology may be suspect but there is good evidence that in some cases the voices heard by schizophrenic patients are due to misattribution of subvocalised speech. The brain's executive systems fail to monitor certain components of the speech production process and the little inner voice takes on a life of its own.
There can be little doubt that coherent inner speech helps to create and maintain a sense of personal identity; the sense that we are unified, continuous beings. So what happens when the inner voice falls silent? Scott Moss, a 43-year-old clinical psychologist, was appointed to a senior post at the University of Illinois. On the same day that he passed the physical examination for incoming staff, he suffered a debilitating stroke that virtually abolished his capacity for speech. He lost not only the ability to converse with others but also to engage in self-talk. He later wrote of his experiences and the process of recovery, describing the condition of total wordlessness as being like confinement to a continuous present. "I did not have the ability to think about the future," he says, "to worry, to anticipate, or to perceive it… I simply existed… I could not be concerned about tomorrow." Nor, in his verbally disconnected state, did he have much concern for his wife and children.
I got off the train at Plymouth. Mr Kafka, I had learned, was going on to Penzance to visit his father - who lived alone, who had been ill, who would be pleased to see his son after so long but would not know what to say. Who always kept himself to himself.
