What's the significance of the lighthouse in Virginia Woolf's "In The Lighthouse?"

The Lighthouse symbolizes human desire, a force that pulsates over the indifferent sea of the natural world and guides people’s passage across it. Yet even as the Lighthouse stands constant night and day, season after season, it remains curiously unattainable. James’ frustrated desire to visit the Lighthouse begins the novel, and Mrs. Ramsay looks at the Lighthouse as she denies Mr. Ramsay the profession of love he wants so badly at the end of Chapter 1. James, finally reaching the Lighthouse in Chapter 3 a decade after he’d first wanted to go, sees that, up close, the Lighthouse looks nothing like it does from across the bay. That misty image he’d desired from a distance remains unattainable even when he can sail right up to the structure it’s supposedly attached to. The novel’s title can be understood as a description for experience itself: one moves through life propelled by desire towards the things one wants, and yet seems rarely to reach them. One’s life, then, is the process of moving towards, of reaching, of desiring. It is “to” the Lighthouse, not “at” it