What is Thoreau's doctrine of simplicity as described in Walden?

Thoreau
believes that through simple living, one can have what is most important in life.  He explains
his doctrine of simplicity in Chapter 2, saying, "as long as possible, live free and
uncommitted...we are happy in proportion to the things we can do without". Thoreau tells
how he once thought about buying a farm, but realized that he could better experience and
appreciate the important things in life, such as the beauty of nature and the landscape around
him, without being tied down by ownership of material things.