SOLITUDE
Thoreau is saying that we can live our lives to ourselves and not be desperate for human interaction. Thoreau wants us to appreciate all that there is to life. The next human being not on Earth is as far away from you and any other person on the planet.
Full Quote: “This whole earth which we
inhabit is but a point in space. How far apart, think you, dwell the two most distant inhabitants of yonder star”