Long before Freud, dreams were lauded as sources of knowledge, providing information about the dreamer’s present situation and future prospects. Dreams never quite belonged to their dreamers, since the hidden meaning was not immediately accessible. This required the help of an interpreter or prior training in the art of deciphering. Only then could the dream yield its secret message.

With Freud, the status of dreams changed. They were still seen as sources of knowledge, but this time it was more about one’s past than one’s future, and the messages delivered were hardly welcome. They were sexual and murderous, bringing to light aspects of ourselves that we would hardly want to know about. They showed human beings not as autonomous agents but as divided, split between what they wished for at a conscious level and the echoes of their unconscious desire.

Where most of the psychology of the last century did its best to ignore this divided subject, writers and artists have been the main groupings outside the world of psychoanalysis to still acknowledge the facts of the unconscious. In some areas of psychoanalysis, even the psychoanalysts have shied away from the dark side of human nature, preferring a sanitised version which they believe will confer scientific respectability on them.

A recent book by two well-known psychoanalysts defines the human subject as “a rational agent with understandable desires and predicable beliefs who will act to further his goals in the light of these beliefs”. This definition is remarkable in that it could be lifted straight out of an economics textbook. What happened to the Freudian unconscious? Today’s market-led societies have less and less space for the idea that a part of human activity does not serve instrumental aims such as the acquisition of wealth, power or happiness. It doesn’t want to know about unconscious desire, infantile sexuality, hatred, self-destruction and despair.

This is exactly the area that writers and artists colonize. They explore not the rational goals of human activity but precisely what blocks these pursuits, the impediments that give human life both its richness and its agony. By taking these dark threads and magnifying them, they are faithful to the mysterious world of desires and defences that Freud mapped out in ‘The Interpretation of Dreams’.

Freud’s dream theory is nearly always misunderstood. The key is to distinguish between a wish and a desire. Let’s say we are worrying about an exam or a trip to the dentist when we fall asleep. We dream of writing our papers in a wood-panelled room or of a dentist with thick eyebrows leaning over us. Now, the popular misreading of Freud here is to see dreams as equivalent to the fulfilments of wishes. We dreamt of doing the exam or the trip to the dentist to reassure ourselves, to master the experience beforehand and lessen our anxiety. If we passed the exam and the dental work didn’t hurt, all the better: the dream would have done the trick.

But this is not what Freud had in mind. He was interested in the split between what we seemed to wish for in a dream – passing an exam, a painless trip to the dentist – and what the dream actually conjured. The devil lay in the detail. Why the wood-panelled room and why the dentist’s thick eyebrows? These were exactly the points in the dream that were most likely to reveal unconscious desire. The contingent, unimportant details that seemed secondary to the action were the real clues.

Unconscious desire here is like a hitchhiker. It needs something to help it pass through the barriers of repression. And so it hitches a ride with a conscious wish, the kind of preoccupation, worry or fantasy that we might think about in our waking state. When we have the dream, we assume it is about this conscious element, thereby allowing the unconscious desire to slip through. But to track desire, we have to follow the senseless, stupid details. The wood-panelling may lead to thoughts or memories connected with something that happened in a wood-panelled room, the thick eyebrows to a childhood memory of a significant figure.

This mechanism of hitching, which Freud called the dreamwork, is exactly what is at stake in many projects of art and literature. In his classic study ‘Persecution and the Art of Writing’, Leo Strauss catalogued the ways that writers used details to express themselves in regimes where free speech was prohibited. The message would be concealed between the lines. The same processes may function in visual art, as we see in the work of the Russian artists Ilya and Emilia Kabakov. Working in Moscow for many years under a regime where artistic expression was severely limited by state control, they compared their works with the dreams described by Freud. On the surface it seemed an obvious point was being made, but an attention to the detail showed a subversive message.

And this brings us to the real interface between Freudian dream theory and literary and artistic production. What counts is less what’s said than the way it’s said. It has nothing to do with content: it is not about sex or the Oedipus complex or murderous wishes. If these are universals of human life, what matters is the way these are articulated. And, as Freud showed, the key lies in censorship.

The Surrealists provide the best example. Here was a group of writers and artists who, for the most part, were keen readers of Freud and who had paid careful attention to his theory of dreams. They knew about the sexual drives, about Oedipal desires, about the castration complex. Although figures like Andre Breton changed their views about Freud at different moments of their careers, art historians tell us how Surrealism and psychoanalysis went hand in glove.

And yet how exactly did Freud’s dream theory inspire the Surrealists? The unconscious desires that Freud brought to light are in fact no more present than in any other art movement. But what we do find are the MECHANISMS of the dream work, the ways that desire slips through the nets of censorship. When a desire cannot be represented consciously, Freud showed, it will take on the form of some absurdity. Two objects that could never be juxtaposed in reality become so in the dream: an artichoke and a human head, a fish and a bicycle. They are condensed into one, as a way of disguising desire.

This is just what the surrealists took from Freud. When Max Ernst made his Oedipus pictures, he didn’t show a boy with his mummy, but hybrids of animal and human figures in unreal scales and situations. These juxtapositions could not happen in real life, just as in Dali’s work we continually see things next to each other that couldn’t be so empirically: bodily fragments next to landscapes and rocks, strange creatures part-human part-animal, machines with flesh, living bodies and objects improbably enlarged and reduced in scale. These impossible creations are exactly the results of the dreamwork described by Freud: where desire cannot be represented directly, it takes the form of a distortion of reality, a strange convergence of the elements of our everyday life in bizarre and impossible configurations. The title of the big Tate show of Surrealism a few years back ‘Desire Unbound’ was thus misleading: desire for the Surrealists was absolutely bound, and it was the mechanisms of binding and distortion that so inspired them.

Through this technique, the Surrealists did for art what Freud did for dreams, slips of the tongue and symptoms. Rather than seeing them as contingent and meaningless aspects of existence, worthy of little attention, he turned them into enigmas to be deciphered. With Surrealism, a painting or sculpture or collage became less an object to be looked at than a QUESTION. The works of art made their viewers ask: what does this mean? Just like a dream, they called out to be interpreted. Art became less an access to meaning than a barrier to it, one which nonetheless held out the promise of interpretation.

What allowed the surrealist artists and writers to do this was an emphasis not on the CONTENT of desire but its FORM. What they took from Freud was a passion for the dreamwork, the mechanisms of distortion and displacement rather than what apparently lay beneath these. This is a legacy which was been taken up in various ways by the experimental novels of the twentieth century. The French novelist Marie Darrieusecq has described how her own process of writing owes so much to her study of dreams that she is now training as a psychoanalyst. She does not see this as a reason to give up writing, and focuses on what the two professions have in common: an attention to desire and deciphering, to detail and interpretation, and to the formative power of words on our lives.

Dreaming, for her, is a production. Something is actually built out of the repressed desires of the unconscious. And this mirrors, she says, her own construction of her novels. Just as Freud had said that a dream should be broken down into its consituent elements rather than interpreted as a whole, Darrieussecq’s books involve multiple threads that lead in different directions. A complete view, a single perspective that would resolve everything is ruled out. She quotes Freud that “a dream must be broken up into fragments”, the coherence of its surface content being mere illusion.

This coherence is the result of what Freud called ‘secondary revision’. Dreams are airbrushed, contradictions are passed over in favour of a streamlined narrative. We all do this when we remember our dreams, our ego glossing over the points of disturbing or inconsistent material. The existence of a discipline like literary studies is in a sense a response to this process. Instead of seeing a fictional world as coherent and transparent, it focuses on contradictions in texts, odd details and anything, indeed, which would render the literary creation more complex. As with dreams, we expect that a writer always puts more into their creation than they are consciously aware of.

This fascination with the logic of dreams is echoed by Hanif Kureishi, a writer whose knowledge of psychoanalysis is more extensive than that of many analysts. Speaking from a study crammed full of psychoanalytic books, Kureishi remembers how he was first given Freud’s ‘The Interpretation of Dreams’ by his uncle. Like Darrieussecq, he was intrigued by how Freud follows the tiniest detail, allowing it to unravel into what might turn out to be a crucial question of the dreamer’s existence. His characters, likewise, are so often caught between their conscious wishes and their unconscious desires, experiencing the tension between the two as suffocating and inhibiting. Accessing the desire will then take place in moments of violence or transgression.

Kureishi compares these moments to when we wake up from a dream. We have come too close to something, perhaps the very thing that we most desire. We long for it, we gravitate towards it, but we cannot process it. It’s too much for us. So isn’t a desire, he asks, ultimately the same thing as a fear? Dreams are the privileged space in our lives where we can approach the unconscious forces that have shaped our existence, but can we really get too close? We flee from what is most real in dreams to return to the more dreamlike state of mundane reality.