SPICE is designed to address the age-old question, How did we get here? How did galaxies like our own Milky Way form and evolve, how do planetary systems like our Solar System develop, and how do planets like Earth acquire their life-enabling water? SPICE is a spatio-spectral interferometer designed to image protoplanetary and debris disks and measure the spectra of many individual distant galaxies to help answer these questions. SPICE will apply century-old interferometry techniques for the first time in space to achieve unprecedented resolution matching that of the Webb telescope but at ten-times longer far-infrared wavelengths. With cryo-cooled telescopes and state-of-the-art detectors, SPICE offers sensitivity about 10 times that of the Herschel Space Observatory, the most powerful far-infrared telescope to date. SPICE provides a moderate-resolution spectrum in every spatial pixel, and the spectrum is full of information about physical and chemical conditions in the objects studied, as well as the redshifts and distances of galaxies.