Henry David Thoreau writes in his Walden that he went into the woods because <em>he wished to live deliberately. </em>
Thoreau asserts that he went to his farm to seek solitude, but not in the Hollowell Mortgage. So, as an alternative, he choose primitive and inexpensive farm at Walden.
Therefore, the main concept for which the author went into the woods was to seek solitude. Thus option 4 is correct.
