  We calculate the Casimir force on an isolated dielectric sphere in an
ensemble of $N$ spheres due to multiple mutual interactions of the collection
of spheres. In particular we consider dielectric spheres immersed in some other
background dielectric. As an example, the Casimir force between two and three
spheres at zero and finite temperature is evaluated. For a very large number of
spheres, we consider a large-$N$ scaling limit of the Casimir force.
