  We summarize the physics motivations for future accelerators at CERN. We
argue that (a) a luminosity upgrade for the LHC could provide good physics
return for a relatively modest capital investment, (b) CLIC would provide
excellent long-term perspectives within many speculative scenarios for physics
beyond the Standard Model, (c) a Very Large Hadron Collider could provide the
first opportunity to explore the energy range up to about 30 TeV, (d) a
neutrino factory based on a muon storage ring would provide an exciting and
complementary scientific programme and a muon collider could be an interesting
later option.
