Part of where Emerson's claim is substantiated is in his basic idea that individuals cannot appreciate what is great and valid if they blindly follow prevailing social trends.  Simply put, Emerson believes that the truly exceptional artist or thinker is one who is able to demonstrate something new and so intensely brilliant that the conformist social order would fail to appreciate it because of its radical nature.  For example, this can be seen in art.  Emerson believed that the truly talented artist will have to accept, to an extent, that they will not be fully embraced by the social order in which they write.  That is because Emerson believed that great art is composed by individuals who are willing to take risks and challenge prevailing attitudes.  Emerson believed this in his own setting and in understanding his contemporaries.  One of the basic ideas of Transcendentalism involves being true to one's voice and one's own identity as an artist. Should this fly in the face of social acceptance, Emerson is fine with such a trade- off.  To this end, Emerson's philosophy asserts his own consolidaion of intellectual merit. Simply put, Emerson was able to to dismiss criticism of his ideas as proof that "to be great is to be misunderstood."  Certainly, this was not his intent, but it turned out to be quite a convenient shield from his detractors.