In Self-Reliance, what does Emerson believe that individuality means?
In Self-Reliance, Emerson exhorts his audience,
There is a time in every man's education when he arrives at the conviction that envy is ignorance; that imitation is suicide; that he must take himself for better for worse as his portion; that though the wide universe is full of good, no kernel of nourishing corn can come to him but through his toil bestowed on the plot of ground which is given him to till. The power which resides in him is new in nature, and none but he knows what that is which he can do, nor does he know until he has tried.
Individuality means relying upon oneself, being a non-conformist, trusting one's intuitions, having integrity, recognizing one's own talents. Each person has a unique perspective and a unique role to play in the world; each person must trust in himself, as the "power which resides in him" is the power to think and to act independently of society which is in conspiracy against the individual.
In order to have a worthy existence, a person must be an individual; otherwise one sacrifices oneself to society which "is in conspiracy against the manhood of every one of its members." For, in society--this "joint-stock company"-- individuals sacrifice their liberty. Only in being an individual, a non-conformist, is a person truly free and self-reliant and achieve goodness through his own doing. Emerson implies that an individual can achieve goodness only by striving for it. Thus, goodness becomes a goal that lies within any individual's grasp.