End of Emerson's speech

In today's class we went on reading The American Scholar. In his last paragraph of his speech, Emerson refers to the reason of his speech- to make american culture more independent from European culture. With sentences like "He must be an university of knowledges", he tells the Scholar to be interested and find out more things so that his kowledge becomes broader.What I do not really understand is what he means by saying "The world is nothing, the man is all". Why should the world be less important than the man?