What is Fitzgerald's purpose in contrasting the images of "hard rock" and "wet marshes" in the following passage from The Great Gatsby? "And,...

Consider a house built on a foundation of hard rock. It is stable and has a solid base.
People who maintain such conduct have a solid moral base. They cannot be shaken, as they are
firmly rooted in deep and true values. I would argue that there aren't any such people in this
book; evennotes in this selection that "...represented everything for which I have an
unaffected scorn." Nick himself complacently goes along with much of the illicit activity
in the book, so he's not firmly rooted in "hard rock," either.

Most
of the , therefore, have built their morals on "wet marshes." Their values shift with
time. What is true today may not hold true tomorrow. Their lives are somewhat fluid, changing
with the rise and fall of life's tides.certainly fits this sort of description; his only even
potentially positive character trait is his wealth, but even that is acquired through family
inheritance, not through his own abilities. He's an abuser of women and a
racist.leaves...