Final answer:
Virginia Woolf uses the comparison between Shakespeare and his fictional sister Judith in her essay to emphasize the barriers women faced and the lost potential due to gender inequality. This comparison establishes the central idea of the text, highlighting the need for financial independence and personal freedom for women to achieve literary success.
Step-by-step explanation:
In Virginia Woolf's essay A Room of One's Own, the comparison between Shakespeare and his fictional sister Judith serves to explore the central idea of gender inequality, specifically in the realm of literary and creative opportunities. Shakespeare, representing the pinnacle of literary success, is contrasted with Judith, who is denied the same opportunities due to the societal constraints of her time. This powerful rhetorical device exemplifies the obstacles that women faced and the untapped potential of women's contributions to literature and art. Woolf uses this narrative to emphasize the importance of financial independence and personal freedom for women, illustrating that without these, the world will continue to be deprived of potential literary masterpieces by women.