  We present the scientific case for a future space-based telescope aimed at
very high spatial and temporal resolution imaging of the solar photosphere and
chromosphere. Previous missions (e.g., HINODE, SUNRISE) have demonstrated the
power of observing the solar photosphere and chromosphere at high spatial
resolution without contamination from Earth's atmosphere. We argue here that
increased spatial resolution (from currently 70 km to 25 km in the future) and
high temporal cadence of the observations will vastly improve our understanding
of the physical processes controlling solar magnetism and its characteristic
scales. This is particularly important as the Sun's magnetic field drives solar
activity and can significantly influence the Sun-Earth system. At the same time
a better knowledge of solar magnetism can greatly improve our understanding of
other astrophysical objects.
