Every reader of a book analyses a physically fixed text. The book is a piece of information, a sentiment or a story that remains stuck in time and space. While the reader glances across the words, the messages and images they convey crystallise within her mind.

However, the best books should act as a kind of sub-editor of the information we already hold. The act of reading should cause a sift through our raw matter – rejecting what is superfluous, changing passive clauses to active ones - to establishing a coherent argument that forms through proposition, investigation, and results in evaluation.

Good books reorder the language that we already use to offer us emotional or intellectual clarity. And this stays fixed until we come in contact with another illuminating text. Like a running news story that undergoes revision due to an up-date, we find we must again question our previously held knowledge and emotions. Together, these texts make up the stations on our path to a higher degree of awareness and intelligence that can then be translated into pragmatic good. Or so we hope.

But what if the transient quality of the mind could also be true of the text itself? A lecture, recently given by the academic Johnson Matthews in a packed lecture hall near Fitzroy Square, made this proposition, as he held aloft, what he described as, the only "fluid novel" in existence.

Matthews is a sixty-five year old professor of English at the University of London and a follower of the post-modernist camp that has, depending on your view, either condemned literary criticism or saved it from obscurity.

However, no one could refute the fact that Matthews' discovery of The Second Homecoming was the literary scoop of the decade. From its exterior, the book seemed like nothing irregular - a cheap leather-bound novel of around 220 pages, with its pages ripped open by an envelope knife.

It looked as though it had been read many times and, although Matthews had examined the text thoroughly, his notes had not adulterated its paper, nor were the pages loose from the spine. Matthews also assured us that the contents were unlikely to be of great critical worth. Its language is often clichéd, he said, the plotting unoriginal and its characters half-formed.

Matthews told the audience that this was the only copy of this novel in existence but, he said, if there had been others published, it was unlikely that the texts inside would now match. For reading both back-to-back today would be like reading two different books altogether. But this would not have been the case, said Matthews, at their time of publishing.

Only one similarity would remain, he said, the title – The Second Homecoming – and the author – Jeremiad Anthony – as printed on the front page. It is likely that the publication date, as printed on the fourth page, was 1901, but Matthews cannot confirm this to be accurate.

"What do we know of this novel when it was written?" asked Matthews. "Very little."

It was Anthony's only novel and, except for a few newspaper interviews that show he was a Shropshire schoolteacher, nothing else is known of his life.

From these antique news reports, Matthews discovered that the original story seems to have concerned a prisoner, David, who returns to his hometown after serving time in prison for a violent act. Although there is suspicion among the locals, he finds the girl that previously scorned him, Sarah, now finds him attractive. But David's experience of prison, and his own violent nature, still haunts him.

But nothing of this story remained in the book the Matthews held in his hand.

"This book has changed unaccountably since that time. And when I open the book and read a few passages, close it again and reopen the book at that same precise place, the words that I read will no longer exist in the same form as before."

After someone has read The Second Homecoming, explained Matthews, the words, without any intervention, transform themselves to reflect the reaction of that person to the text, while still retaining the semblance of a plot, story and characters within 220 pages.

"What is the story now?" said Matthews. "I do not know. I can tell you what the book was about the last time I read it but, if you were to read the book again, it may be very different. The reader unconsciously rewrites the story."

To demonstrate this, Matthews read aloud a passage at random.

"'David was unsure of his route back home. But he had to return quickly. He had to bring this message to Sarah and nothing would stop him. The night fell and dark clouds gathered around the moon. Its celestial light gilded the branches and bracken with a silver hint. All the trees seemed like the closed ranks of a proud and silent army. Across and under his feet, he could only feel thicket and weeds. Now he was no longer on the path. There was a rattle of branches and a shrill, loud scream.

David shook and turned around. Across the glow of the moon, flew the silhouette of a crow.'"

Matthews then kept the book open on this page, moved from his lectern and up to the audience, and showed the page to a student in the front row. The student nodded to confirm that the passage was the first paragraph of page 57.

Then Matthews closed the book and reopened it on page 57. He showed the page to the student, who nodded again. But, after the student had given a quick glance through the first paragraph once more, he took a deep intake of breath and looked noticeably disturbed.

Again, Matthews read from the top of page 57.

"'As the audience left the theatre and gathered on the steps of the concert hall, David jostled his way through the thick crowds and walked into the main auditorium. The fixtures looked different. He was sure it had either been renovated since his last visit. But he had little time and needed to find Sarah fast, before she went home. Then he saw the back of a bob-cut of black hair and her slim body. But it was held around the arms of another broad-shouldered man.

Angrily, David slapped his hand down on the woman's shoulder.

But as the face turned around, he realised it was not Sarah."

Once more, he showed this to the student, who nodded worriedly. The audience gasped.

"You will notice that the text reflects the themes in my conscious mind," said Matthews. "Instead of the lecture room where I now stand, the book distorts this into a theatre. Consistent with the themes of transformation that I have spoken about this evening, we have the renovation of the auditorium. Yet the main elements of the story remain. Both are part of a chase sequence, where the man needs to find a woman. Both end with a deception."

Matthews returned to his lectern. He took a brief respite, consulted his notes and then read on.

"This sets up some interesting questions, many of which I have researched. For example, what happens when you write down a passage from the story and then store this far away from the text? Well, the text is fluid in any form, so if any reproductions are made, the copy too will transform. The text can never be read in exactly the same way more than once, and the alteration takes no more than a split second to happen. A reader will not be able to see the words change or rearrange themselves. They will just suddenly appear different.

"I also analysed what happens when two people read the same passage at once. I discovered that the resultant text would contain both individuals' reactions.

"One question in particular has also interested people of my critical persuasion: who is the author of this text? The first argument holds that Jeremiad Anthony is the author. His name appears on the front, the original text, plot and characters came from his imagination. This is a reasonable conclusion. But now none of these words are any longer part of his creation. They do not belong to his consciousness. Anthony's contribution to the manufacture of this novel is barely different from the craftsmen that mixed the gum for the spine and treated the leather for the cover.

"Could the last person to read the novel be the author? After all, the book contains that person's reactions. However, the text will also contain the remnant layers of previous texts, traces left behind from other readers.

"So are all the people that have, over the century, read the novel and contributed to its present form its joint authors? Possibly. Although undoubtedly true, does this not open the credit of authorship far too wide? For how does this not make this book different from other novels? All novels may carry one name on the front, but a variety of experiences will co-author an author's text – his background, the influences of his family, his wife, his children and his friends, his language and society itself.

"So could the book take the credit for its own inception? The language seems to be do most of the hard work. While the reader may interact with the book passively, the language then enacts what seems to be a highly technical exercise in psychic and psychoanalytic research, couched within a literary framework. But language has no consciousness; an entity must have a consciousness to be able to write a novel.

"It is not language that activates this novel, it is the reader. Language, here, is the camera that films a reader against a blue background, before filling in the text around that person and creating an original image.

"Once could argue that The Second Homecoming is the only truly useful book, as it will tell you about yourself in such an original and accurate way that other texts, hampered by their tangible nature, can only hope to achieve indirectly.

"But for a reader to arrive at a higher awareness through reading this novel, one needs the training or instincts of a literary critic. A critical dissection of the plot, characters and descriptions allows one to arrive at a conclusion that opens the lock to one's own character.

"If anyone in a position of personal crisis or psychological discomfort was to read this book, a literary critic with some training in psychology could then analyse the text and divulge the symptoms of an individual's problems. Of course he could only have one chance to do this, before the psychologist-critic, having read the book, was himself able to be analysed."

Matthews leaned back away from his lectern, put down his reading glasses and turned to the mass of students. "Now, are there any questions?"

The students in the packed lecture hall looked at one another for about thirty seconds. A few seats shuffled, one or two people picked up their bags and walked out of the door.

Suddenly, one lone hand waved in the air. The student, a twenty-year-old man with a beard that reached from ear to ear, asked a question with such confidence that a murmur of enthusiasm rolled round the hall before Matthews had a chance to answer the query.

"How much is the book worth?" asked the student.