The sea as symbolic of life
The ebb and flow of life. When the image is portrayed as being harmonized, the sea represents a great confidence and comfort. Yet, when the image is presented as disjointed or uncomfortable, it symbolizes disassociation, loneliness, and fear.
Doubling
Many critics describe Septimus as Clarissa's doppelganger, the alternate persona, the darker, more internal personality compared to Clarissa's very social and singular outlook. Woolf's use of the doppelganger, Septimus, portrays a side to Clarissa's personality that becomes absorbed by fear and broken down by society and a side of society that has failed to survive the War. The doubling portrays the polarity of the self and exposes the positive-negative relationship inherent in humanity. It also illustrates the opposite phases of the idea of life.
The intersection of time and timelessness
Woolf creates a new novelistic structure in Mrs. Dalloway wherein her prose has blurred the distinction between dream and reality, between the past and present. An authentic human being functions in this manner, simultaneously flowing from the conscious to the unconscious, from the fantastic to the real, and from memory to the moment.
The world of the sane and the insane side by side
Woolf portrays the sane grasping for significant and substantial connections to life, living among those who have been cut off from such connections and who suffer because of the improper treatment they, henceforth, receive. The critic, Ruotolo, excellently develops the idea behind the theme: "Estranged from the sanity of others, rooted to the pavement,' the veteran [Septimus] asks for what purpose' he is present. Virginia Woolf's novel honors and extends his question. He perceives a beauty in existence that his age has almost totally disregarded; his vision of new life... is a source of joy as well as madness. Unfortunately, the glimpse of beauty that makes Septimus less forlorn is anathema to an age that worships like Septimus' inhuman doctor, Sir William Bradshaw, the twin goddesses Proportion' and Conversion.'"
Social commentary
Woolf also strived to illustrate the vain artificiality of Clarissa's life and her involvement in it. The detail given and thought provoked in one day of a woman's preparation for a party, a simple social event, exposes the flimsy lifestyle of England's upper classes at the time of the novel. Even though Clarissa is effected by Septimus' death and is bombarded by profound thoughts throughout the novel, she is also a woman for whom a party is her greatest offering to society. The thread of the Prime Minister throughout, the near fulfilling of Peter's prophecy concerning Clarissa's role, and the characters of the doctors, Hugh Whitbread, and Lady Bruton as compared to the tragically mishandled plight of Septimus, throw a critical light upon the social circle examined by Woolf.