Ulysses in a 1919 essay, she wrote:

Examine for a moment an ordinary mind on an ordinary day’ – and ... imagine the possibility of a new fiction that comes closer to reflecting this ‘life’.

This "new fiction" is explored in Mrs. Dalloway.

Modernism is a philosophical and artistic movement that began in the late nineteenth and early twentieth centuries. The movement was fueled by a desire to break from tradition in order to more accurately reflect the events and feelings of the time, including a sense of disillusionment resulting from World War I. Among the many characteristics of modernist literature are fragmented writing, focus on inner thoughts, a break from traditional linear writing styles, and a shift toward stream-of-consciousness writing style.

In her novel Mrs. Dalloway, Virginia Woolf demonstrates many of the characteristics typical of modernist literature. She strays from tradition and adopts a non-linear writing style. There are forward jumps in time, flashbacks, and multiple points of view. Woolf places a great deal of focus on the inner thoughts of the characters and often jumps from one thought to another with little or no transition. She uses a fragmented writing technique and employs a stream of consciousness style. Characters' thoughts are often incomplete. The sentences in the novel are often long and complicated. All of this is designed to mirror the meandering of human thoughts, which are often disorganized and non-linear.

Through Septimus's character, Woolf highlights the sense of disillusionment felt by many during and after WWI. Septimus suffers from shell shock (post-traumatic stress disorder) after serving as a soldier in the war. His doctors do not fully understand him or his condition and fall tragically short of helping him. He makes the decision to take his own life, choosing to die on his own terms, since he was not able to live on his own terms.

Modernist literature was popularized post-World War One, and is generally thought to have lasted between the early 1900s to the early 1940s.

Generally, modernist literature is a departure from the conventions of 19th century prose. Modernist authors like Virginia Woolf eschewed the chronological continuity and formulaic story-telling of Victorian literature. Instead, they highlighted post-war disillusionment, alienation, and pessimism through stream-of-consciousness narratives that captured the random associations, thoughts, and emotions of individual characters.

In Mrs. Dalloway, Woolf shares with her readers the inner monologues of characters like Clarissa Dalloway and Peter Walsh. Through their inner stream-of-consciousness narratives, we are given glimpses into the sense of alienation and disconnect felt by individuals attempting to navigate the upheaval of a post-war reality. Mrs. Dalloway's thoughts vacillate between cynical despair, resignation, and joy.

For example, although she prizes the independence her marriage accords, she also harbors regrets in rejecting her former lover, Peter. Clarissa finds no contentment in either Richard's characteristic reticence or Peter's profuse vulnerability:

For in marriage a little license, a little independence there must be between people living together day in day out in the same house; which Richard gave her, and she him. (Where was he this morning for instance? Some committee, she never asked what.) But with Peter everything had to be shared; everything gone into. And it was intolerable...

Clarissa tries to remind herself that Peter once called her "cold, heartless, [and] a prude." In addition, she's heard rumors that he married one of those "silly, pretty, flimsy nincompoops." Yet, she is preoccupied with thoughts of him throughout the novel.

Peter himself nurses similar regrets in life. When he visits Clarissa, he is obsessed with impressing her. He fiddles with his pocket-knife as he wrestles with his thoughts. Finally, he expresses his overwhelming emotions in the same tearful sentimentality she despises.

For Heaven's sake, leave your knife alone! she cried to herself in irrepressible irritation; it was his silly unconventionality, his weakness; his lack of the ghost of a notion what any one else was feeling that annoyed her, had always annoyed her; and now at his age, how silly!

I know all that, Peter thought; I know what I'm up against, he thought, running his finger along the blade of his knife, Clarissa and Dalloway and all the rest of them; but I'll show Clarissa—and then to his utter surprise, suddenly thrown by those uncontrollable forces thrown through the air, he burst into tears; wept...

Peter's "weakness" both repels and fascinates Clarissa. Yet, as she revels in Peter's presence, she frets about her marriage to Richard. Clarissa veers between inner ecstasy and despair, fantasizing that Richard has left her and she is "alone forever." In short, feelings of unease, doubt, and apprehension haunt the thoughts of characters in the novel, highlighting the pessimism of the age of modernism. For more on Mrs. Dalloway and the age of modernism, please refer to the links below.