'Walden' is an elegant and at times moving journal of Thoreau's sojourn in living in/with nature. His observations and thoughts concern a variety of subjects such as growing your own food, building a house, watching the patterns of animals and plants, etc. But Thoreau also reflects on the human ways of life, and isn't afraid to voice his opinion on such matters as diverse as economy or solitude of living.
It's difficult to agree with all he writes, because it is so much, so and so disparate, but on the whole 'Walden' leaves an impression. Especially the way Thoreau describes his minute observations of seemingly simple natural phenomena is impressive, and lends the text a spiritual character at times, at least to those so inclined.