Walden: Theme Analysis

The Natural World
By choosing to live at Walden Pond and doing so in a self-sufficient way as possible, Thoreau immersed himself in what he describes as the ‘tonic of wildness’. His condensed record of his experiences makes up this work and it is necessarily primarily concerned with what he sees in nature. This ranges from the sounds of the birds he hears, to the escapades of squirrels, and to the effects that the changing seasons bring about.  
The descriptions of the water in the pond, for example, not only give great detail to his perceptions, but also demonstrate how much he immersed himself in this life. In the two years he spent there, one can see that he tried to infringe as little as possible on the environment he intruded upon. He sets an example to earlier and later colonizers that have paid no regard to the natural world.
The Passing of the Seasons
Although he spent two years at Walden, this book encapsulates his time over a one year period. In doing so, he is able to focus on the changing seasons and how greatly this affects the environment. Because of his adopted lifestyle, he is closer to nature than he (or many of his readers) would have been previously and his records illuminate both how beautiful and influential the seasons should be on our lives. It is also telling that he makes a point of showing how he lives according to the time of year and consistently demonstrates how simple it is to adapt to the heat and then the cold.
 
Work and Pleasure
Thoreau pointedly shows that although it is necessary for him to work in order to keep his beans growing well, for instance, he also stresses that we should not be slaves to our jobs. By example, he demonstrates that if one works sufficiently and refrains from supposed luxuries (such as tea and coffee), it is possible to live a freer life than one that is dominated by work, paying a mortgage and being over-heated rather than warm.
His writing shows us that it is possible to enjoy life if only we could broaden our horizons as he did. By living within his means, and because he is not swayed by capitalism, he also highlights how one can takes time to observe what is happening around us with pleasure.