What are the tenets of nihilism in Turgenev's Fathers and Sons?

Nihilism is probably the most dominant theme to come out
of Turgenev's work.  It is shown to be a part of the generational gap between the older
culture and the younger culture.  Turgenev is extremely skilled at showing an increasing
chasm in Russian society and that nihilism is a part of this.  The abandonment of "old
world" values and the embrace of a more cold and calculating approach to consciousness
is part of this understanding of nihilism.  For example, while the older generation in
the novel is shown to love poetry and the elements of life that emphasize feelings and
sensuousness, the younger generation is shown to be the opposite, favoring more
practicality and more of an approach that favors scientific determinism.  Barzarov's
declaration that a "chemist is twenty times more useful than a poet" reflects this
nihilism which is also part of a generational shift.  Turgenev argues that this is 
where the relationship between older and younger people lie.  Due to the fact that this
vision of nihilism presents an incommensurate notion of the good with the values held by
the older generation, one of its tenets is that Russian society is being stretched with
both sides advocating their notion of the good.  The ending of the narrative is one
where nihilism is felt througout life, but rejected in the end for those "old world"
values that bring more meaning to life and to one's state of being in the world.  In the
end, a poet is more meaningful to articulate the pain that one feels in such a
condition.  The chemist lacks the capacity to do so, which is why Turgenev argues that
Bazarov will still experience those values that bring meaning even after
life.