  The periodic motion of a classical point particle in a one-dimensional
double-well potential acquires a surprising degree of complexity if friction is
added. Finite uncertainty in the initial state can make it impossible to
predict in which of the two wells the particle will finally settle. For two
models of friction, we exhibit the structure of the basins of attraction in
phase space which causes the final-state sensitivity. Adding friction to an
integrable system with more than one stable equilibrium emerges as a possible
"route to chaos" whenever initial conditions can be specified with finite
accuracy only.
