  We study large scale collective dynamics of isoscalar type and examine the
influence of interactions residual to independent particle motion. It is argued
that for excitations which commonly are present in experimental situations such
interactions must not be neglected. They even help to justify better the
assumption of locality, both in time as well as in phase space, which is
necessary not only for such classic approaches to collective motion as the
"cranking model" but also for the more general picture of a transport process.
With respect to dissipation, our results are contrasted with those of wall
friction.
