Thoreau's philosophy on moral individualism is distinctively American. The main concept in his philosophy is that of "independence". First of all, he declared his independence of the deep-rooted Calvinism of New England, and especially the doctrine of the Original Sin, by insisting upon man's aboriginal innocence and the responsibility of each individual to recover it. He also decalred his independence of tradition and even of his past self. This was the meaning of his celebration of "morning" in his book Walden. Morning is his great symbol of rebirth and re-generation; it is the opportunity for a new start.

"My peculiar ability to serve the public; I am useful in my way". Each person is meant to be useful, not for every purpose, but in his or her distinctive way, and is responsible for discovering and perfecting that way. To discover and perfect our way is what Thoreau refers to as "our business". "Not until we are lost, in other words, not till we have lost the world do we begin to find ourselves and realize where we are and the infinite extent of our relations". The world that we must lose is the inherited world which was conferred a self upon us, but the self we discover newly related to the world in original terms.

According to Thoreau, all persons by nature of personhood are innately invested with unique potential worth. His term for that is "genius", and regards it as that person's "reality" or true self, which his actual self may or may not reflect. This exists in potentia. In childhood one's distinctive potentiality is latent but during adolescence the responsibility for self-discovery starts. According to him, self-discovery can only occur experimentally, and it consists in the discovery, not of an idea of ourselves, but of what "rightfully attracts" us. In other words our genius or innate self subsists as a system of preferences and aversions. Our first responsibility is the work of progressively actualizing our distinctive potential worth. This is the primary moral business. "Let everyone mind his own business, and endeavor to be what he was made".

Economy: "to affect the quality of the day"; it refers to the ability to recognize the possibilities of value-actualization that each day, indeed each hour and moment present.

Simplicity: the absence of complexity. The principle here is "no waste of potential value"; do not desire or own things whose potential values you cannot actualize, or whose potential values you can only actualize at cost to your self-actualization. The discovery of our true needs is self-discovery.

Nature: the phenomena of the world exclusive of man and his effects. With respect to self-discovery, when a person is seeking the truth in himself it is honest company he should keep, and he will find it in nature.

The Stoic nomos/physis distinction is relevant in his philosophy. Man is by nature the convention-making animal, but this does not dissolve the above distinction if we retain the idea that by nature persons have particular moral jobs to do. Each individual is to actualize particular possibilities, and conventions, which is generalized habit, is incapable of making the particular determinations. "Our business" is in the case of each of us a particular business, and must be found out for ourselves.