Clearly the central themes of "Self-Reliance" by Emerson are very strongly expressed in Walden by Thoreau. Emerson's key argument in "Self-Reliance," for example, is of the evil of society and how society is set against self-reliance because of the way in which it is designed to support each member of it by a collective sacrifice of what makes them human. Consider this quote from Emerson's essay:
Society everywhere is a joint-stock company in which the members agree for the better securing of his bread to each shareholder, to surrender the liberty and culture of the eater. The virtue in most request is conformity. Self-reliance is its aversion. It loves not realities and creators, but names and customs.
Clearly then, Emerson believes that society is something to avoid as it saps the ability of the individual to be self-reliant and to commune with nature. In the same way, in Thoreau's work, we see that he adopts Emerson's belief in his choice of abode and lifestyle:
When I wrote the following pages, or rather the bulk of them, I lived alone, in the woods, a mile from any neighbour, in a house which I had built myself, on the shore of Walden Pond, in Concord, Massachusetts, and earned my living by the labour of my hands only. I lived there two years and two months.
Thoreau's choice to live out Emerson's belief and make himself self-reliant by living an isolated life away from civilisation and the discoveries he is able to experience in nature as a result clearly elucidates Emerson's argument about society and how it represents the nemesis of self-reliance.