Discovery & Depth
  In the United States, the National Science Foundation (NSF), anticipating the
no growth in funding, has commissioned a review of NSF-funded astronomy assets
with the goal of determining how to best allocate funding for this decade.
Inputs from members of the US community were sought. It is a matter of simple
arithmetic that for a fixed level of funding many significant aspirations of
Astro2010 cannot be met. Here, accepting the boundary conditions posed above, I
have focused on fields centered on optical astronomy which offer the best
opportunity for progress in this decade and thus offer the highest cost-benefit
ratio. Readers may profit from reading the first seven sections.
