First published as a standalone volume on February 2, 1922, James Joyce’s Ulysses turns one hundred this week. Even if you have never immersed yourself in the modern reimagining of Homer’s seafaring epic, a related phrase may have drifted across your awareness: the name for a narrative technique employed by Joyce, Djuna Barnes, Jean Toomer, Virginia Woolf, and myriad other writers that rub shoulders within the ever-bulging periodic and aesthetic borders of modernist literature: stream of consciousness.

Scholars believe “stream of consciousness” was first used as a description of literary style by the British writer May Sinclair, during a review of Dorothy Richardson’s novels for The Egoist in 1918. Eschewing the “philosophical cant of the nineteenth century” — mannered depictions of the world that passed for “realism” — May prefers the mess of the mind. “Reality is thick and deep, too thick and too deep, and at the same time too fluid to be cut with any convenient carving-knife.” To capture this fluidity, the novelist must “plunge in”, which Richardson does in her monumental thirteen-novel Pilgrimage sequence. “In this series there is no drama, no situation, no set scene. Nothing happens. It is just life going on and going. It is Miriam Henderson’s stream of consciousness going on and on”, writes May. Although James Wood and others have argued that there is nothing uniquely modernist about representing “the movement of the mind” upon the page, the psychological theory of mind that informs May’s review can be traced to a chapter in William James’ The Principles of Psychology (1890).

Harvard professor, physician, investigator of psychic communication, “father of American psychology”, and the brother of novelist Henry James, William James begins “The Stream of Thought” by acknowledging that any psychological vocabulary will be rough-hewn when it comes to the fine-cut facets of mental phenomena, comparing what follows to “a painter’s first charcoal sketch upon his canvas, in which no niceties appear”. But the psychologist is being modest, for he immediately launches into a polished discussion of “anesthetic somnambulists”, subconscious personages, and the possibility of thoughts existing without a thinker. This is all a preface for the larger concept: that our minds seem to ebb and flow with ideas, while emotions behave almost tidally, rising and falling in relation to intangible forces, as if a moon presses gravitationally upon our psychic seas.

James was not the first to analogize the mind as a river — Alexander Bain had used the phrase “stream of consciousness” in 1855 and the Buddhist concept of “mindstream” (citta-santāna), characterizes selfhood in a similar way. In The Principles of Psychology, “the stream of thought” becomes a carefully chosen image for the flux of subjectivity: how ideas, feelings, and sensations, both present and past, cohere into the experience of a continuous self, that ever-present “I”, which meanders through the mind from childhood until our deaths and possibly beyond. Invoking Heraclitus by name, James repurposes his idea — that a person can never wade into the same river twice: “no state once gone can recur and be identical with what it was before. . . . In talking of it hereafter, let us call it the stream of thought, of consciousness, or of subjective life.” Beneath this stream, to continue his fluvial metaphor, sits the silt and pebbled bed of the unconscious, voluntary and involuntary memories, and even alternative persona. In contrast to the theories of Pierre Janet, Jean-Martin Charcot, and other early psychologists who practiced at the Pitié-Salpêtrière Hospital in Paris (and cultivated damaging theories regarding female hysteria), James thought “the fact that the mind contains multiple streams of consciousness which at times rise to the surface was not something to be feared”, writes Alicia Puglionesi. In other words, the self contains multitudes and always has.

If consciousness is a stream, what are the banks and channels that guide its course? James alighted on a concern that would preoccupy spelunkers of cognition in the decades to follow: the deadening effects of habit, the diminishing returns of repetitive pleasures, whether gustatorial, aesthetic, or spiritual. As if trying to refresh the perception of his reader’s glazed eyes, James lapses literary when addressing the topic, assuming the voice of a world-weary male:

From one year to another we see things in new lights. What was unreal has grown real, and what was exciting is insipid. The friends we used to care the world for are shrunken to shadows. . . once so divine, the stars, the wood, and the waters, how now so dull and common! the young girls that brought an aura of infinity, at present hardly distinguishable existences; the pictures so empty; and as for the books, what *was* there to find so mysteriously significant in Goethe, or in John Mill so full of weight?

The turn of the century saw a proliferation of treatises on the dulling effects of routine. Works such as Walter Pater’s The Renaissance (1873) Albert Lemoine’s L’Habitude et L’Instinct (1875), Georg Simmel’s “The Metropolis in Mental Life”(1903), and Viktor Shklovsky’s “Art as Technique” (1917) evidence the widespread concern — voiced by philosophers, art historians, literary theorists, sociologists, and novelists across a wealth of languages — about the way increasingly mechanized, mediated, and urbanized societies downregulate stimulus response. While Pater speculated that “our failure is to form habits”, Samuel Beckett would concede in a 1930 essay on Marcel Proust that the stream of consciousness only appears consistent due to the regulatory effects of habitual action: “Habit then is the generic term for the countless treaties between the countless subjects that constitute the individual and their countless correlative objects.” Though influenced by Henri Bergson, Beckett’s idea may not have been possible without the work of William James, who dedicated a 1914 essay to the topic, and meditated on habit and the continuity of selfhood at length in “The Stream of Thought”.

Art has long offered an antidote to what James describes as the decay of excitement into insipidity. In Percy Shelley’s famous dictum: “Poetry lifts the veil from the hidden beauty of the world, and makes familiar objects be as if they were not familiar”. From Stephen Hero, his early draft of A Portrait of the Artist as a Young Man, to Finnegans Wake, written in a stream of unconsciousness — “an imitation of the dream-state” — Joyce maintained a cryptic interest in the ability of literary language to prompt epiphany, defined, by his character Stephen, as: “a sudden spiritual manifestation, whether in the vulgarity of speech or of gesture of in a memorable phrase in the mind itself. . . . it was for the man of letters to record these epiphanies with extreme care, seeing that they themselves are the most delicate and evanescent of moments.” In Ulysses, the “stream of consciousness” technique not only faithfully represents the mind by violating the supposed objectivity of nineteenth-century realism, as May Sinclair described, but leaves its reader, perhaps, with an enhanced consciousness of their own cognition.

Take, for instance, a scene in the “Lestrygonians” episode that occurs along the waters, when the adman Leopold Bloom crosses Dublin’s O’Connell Bridge over the River Liffey. We begin in the third person, as a narrator describes how Bloom scans the river, finding a clever advertisement — for a London clothier, selling trousers in its Dublin outlet at eleven shillings a pair — mounted on a docked and rocking rowboat:

His eyes sought answer from the river and saw a rowboat rock at anchor on the treacly swells lazily its plastered board.

        Kino’s
        11/-
        Trousers

Good idea that. Wonder if he pays rent to the corporation. How can you own water really? It’s always flowing in a stream, never the same, which in the stream of life we trace. Because life is a stream.

The ad is not summarized or offset by quotation marks: we see it as Bloom does. And suddenly, without marked transition, we are inside his mind, surfing the stream of consciousness as Bloom reflects, like Heraclitus and James before him, on the everchanging fluidity of inner and outer life. It’s a brilliant passage, for — as aqueous advertising seeps into free-flowing thought — Bloom himself becomes an advertisement for Joyce’s style, how the author approximates the treacly swells of cognition, plunging us deep into the thick river of reality.