Shaw punctures men's romantic illusions about women and love through the strong and pragmatic character of Candida in the play. As her name implies, Candida speaks candidly or honestly about love.
Candida, faced with two men who are steeped in romantic illusions about her, faces them both down with her straightforward, commonsensical approach to life. When she talks of needing a new scrub brush, for example, the poetical Marchbanks reacts in horror. Candida says, in response:
What is it, Eugene—the scrubbing brush? (He shudders.) Well, there! never mind. (She sits down beside him.) Wouldn't you like to present me with a nice new one, with an ivory back inlaid with mother-of-pearl?
Eugene replies with
No, not a scrubbing brush, but a boat—a tiny shallop to sail away in, far from the world, where the marble floors are washed by the rain and dried by the sun, where the south wind dusts the beautiful green and purple carpets. Or a chariot—to carry us up into the sky, where the lamps are stars, and don't need to be filled with paraffin oil every day.
Candida shows Marchbanks romantic imaginings to be silly through her own solid grounding in reality. When Marchbanks says:
Oh! don't talk about boots. Your feet should be beautiful on the mountains.
Candida counter his mountaintop vision with:
My feet would not be beautiful on the Hackney Road without boots.
Candida shows herself to be stronger and more realistic than either of the two men vying for her love. As she says to her husband:
Ah, James, how little you understand me, to talk of your confidence in my goodness and purity! I would give them both to poor Eugene as willingly as I would give my shawl to a beggar dying of cold, if there were nothing else to restrain me.
Candida's lack of interest in stirring rhetoric, poetic language, or idealized, abstract concepts such as goodness and purity are what makes real love and a stable, successful marriage possible. To Candida's eyes, a soft-headed romanticism, full of unrealistic expectation, can ruin a perfectly good relationship.
Through his positive portrayal of Candida, Shaw argues for marriage based on reason, intelligence, and pragmatic choices rather than romantic yearnings.