"Envy is ignorance" because it prevents the development of an individual. To wish to be like someone else is to deny one's own potential--"suicide"--and, thus, to remain in the darkness of ignorance. Known for his repeated phrase of "trust thyself," Emerson repudiated the idea of a man's wishing to conform in his envy.
Emerson's essay, Self-Reliance, begins with what he felt was genius:
To believe your own thought, to believe what is true for you in your private heart is true for all men--that is genius.
Trusting oneself, and being an individual are genius, the antithesis of envy. Emerson contends that God has made each person unique with his/her own individual work to do. Therefore, to trust one's own thoughts and actions is very much like listening to God and acting upon His wishes.
"Society everywhere is in conspiracy against the manhood of every one of its members."
For Emerson, the importance of the individual is paramount. "Self-reliance is its [conformity's] aversion." The integrity of one's mind is what matters, not imitation, not envy.