Cleaning as an allegory
There is strange way in which cleaning is much more than meets the eye. In Kondo's theory and practice, cleaning is much more similar to an allegory for mental and emotional freedom and health. When people feel they need something, that is dependence that makes them feel claustrophobic and paranoid. Trying to free a hoarder of their obsessive relationship to possession is an act of spiritual freedom, because their emotions are attached to keeping what they own.
The allegory in question is like the knight slaying the dragon to save someone. Like a dragon, some people hoard possessions without even using them (like a dragon can't use the gold they hoard), and she teaches them to be their own knight, slaying the dragon of fear and saving their emotions from clutter.
Possessions as symbols for emotion
To say that a person has an attachment to an object is to say that they understand the object as a symbol for their own survival. Most people understand that small possessions don't actually matter in their literal survival, but they still panic at the thought of losing their stuff. Marie Condo comes to disrupt that symbolism by fulfilling it. She accepts their emotional attachment and teaches them to mourn the loss.
The "Joy Spark"
Bilbo Baggins has his ring and his sword; those are his heroic weapons. Marie Kondo comes with a weapon of her own, and she passes it along to the reader to help them declutter their own life. The question is whether a possession brings a "spark of joy" to the person upon seeing it or touching it. Her clients will address their possessions one at a time to determine whether they feel joyful. Notice the question is not attachment, but joy. Does the possession feel like a blessing or an obligation? That is the tool she uses for whether she throws something away or not.
Keepsakes
There is a special category of things that Marie Kondo honors above other kinds of petty possessions: Keepsakes. Keepsakes are symbols because they capture something essential and meaningful about a person's journey through life. She mentions relationships here, because keepsakes are often gifts or items that symbolize the birth of a new relationship or a new season of life. These are like religious relics of a person's time on earth, so she does not throw them away. They are symbols of the sacredness of one's experience.
Freedom and health as practice
Instead of viewing freedom from clutter as a thing to be attained, Kondo suggests the reader think of healthy living as a practice. Freedom is the continual confidence that comes from comfortable removing possessions from one's life. They are "free" from individual possessions, but more importantly, they are free from the myth that they depend on things for happiness. They can be healthy by detaching from their clutter.
