Fruit—which often appears as a metaphor for the good things in life—becomes a recurring motif in Walden. It first appears in "Economy" as a metaphor for the finest, simplest, and least materialistic experiences in life:
Most men, even in this comparatively free country, through mere ignorance and mistake, are so occupied with the factitious cares and superfluously coarse labors of life that its finer fruits cannot be plucked by them. Their fingers, from excessive toil, are too clumsy and tremble too much for that.
Here, Thoreau laments that most men become so occupied with "factitious cares" and "superfluously coarse labors of life" that they remain ignorant of its "finer fruits." They work meaningless jobs in pursuit of meaningless items—homes, technology, transportation—and have no energy left to pursue spiritual fulfillment. Thoreau embarked upon his experiment at Walden to solve this very problem; he wanted to prove that the best "fruits" of life could be plucked after people removed all the unnecessary aspects of their lives.
In the book's final chapters, the significance of the fruit metaphors begins to crystallize. Thoreau specifies that "the finer things in life" include the brain, the intellect, the ability to coexist peacefully in nature and divest oneself of material concerns, and the development of one's understanding of the natural world. Fruit-bearing plants become a metaphor for people who become rich but avoid superfluity, and fruit itself also serves as a metaphor for the brain of the old man—"one of the last philosophers"—who comes to visit Thoreau. By incorporating a range of different interpretations of metaphorical fruits, Thoreau establishes the importance of the intellect and makes the human mind seem more a part of the natural world than the modern technological world.
In "Where I Lived, and What I Lived For," Thoreau likens self-creation to artwork via metaphor:
It is something to be able to paint a particular picture, or to carve a statue, and so to make a few objects beautiful; but it is far more glorious to carve and paint the very atmosphere and medium through which we look, which morally we can do. To affect the quality of the day, that is the highest of arts.
Here, the author claims that the highest art is the formation of one's own perspective. He acknowledges the power and beauty of actual art, but he argues that it is more glorious to "carve and paint the very atmosphere" in which we live. This metaphor likens humans to artists, and their lives (or environments) to art. In other words, people can shape their own minds and make life worth living. Modernity remains at odds with this idea; the modern world places such great emphasis on making things, and on producing work, that many people forget their power to create themselves.
This metaphor nicely introduces the idea of self-reliance and deliberate living. It appears right before the famous line: "I went to the woods because I wished to live deliberately." Creating one's own life—and art—requires deliberate intention and effort. Just as an artist spends most of his time dreaming up new ways to hone his craft, regular people must spend more time intentionally crafting their own lives.
This idea appears again in the Conclusion when Thoreau writes about a parable of an artist in Kouroo who rejects petty concerns and strives instead for a transcendent existence. He dedicates himself to his work and becomes a sort of higher being able to produce beautiful works of art—but also able to forge the path of his own life. This anecdote resonates with Thoreau's initial commentary on art because this artist crafts both his projects and his life.