  We put forward a framework for cosmology that combines the string landscape
with no boundary initial conditions. In this framework, amplitudes for
alternative histories for the universe are calculated with final boundary
conditions only. This leads to a top down approach to cosmology, in which the
histories of the universe depend on the precise question asked. We study the
observational consequences of no boundary initial conditions on the landscape,
and outline a scheme to test the theory. This is illustrated in a simple model
landscape that admits several alternative inflationary histories for the
universe. Only a few of the possible vacua in the landscape will be populated.
We also discuss in what respect the top down approach differs from other
approaches to cosmology in the string landscape, like eternal inflation.
