  We present the severe, systematic uncertainties currently facing our
understanding of dust emission, which stymie our ability to truly exploit dust
as a tool for studying galaxy evolution. We propose a program of study to
tackle these uncertainties, describe the necessary facilities, and discuss the
potential science gains that will result. This white paper was submitted to the
US National Academies' Astro2020 Decadal Survey on Astronomy and Astrophysics.
