  We investigate the physical mechanisms of high-energy gamma-ray emission from
the TeV-emitting misaligned active galactic nucleus IC 310. Eight years of data
from the Fermi Large Area Telescope (Fermi-LAT) between 100 MeV and 500 GeV are
reduced and analysed to study the temporal and spectral characteristics of IC
310. Point spread function-partitioned instrument response functions are used
to improve the resolvability of IC 310 from nearby NGC 1275. Systematic effects
due to this choice of instrument response functions and the proximity of NGC
1275 are investigated. We find strong spectral variability and detect the hard
flaring state of IC 310 along with a previously undiscovered soft state in
quiescent periods, and the first detection with Fermi-LAT below 1 GeV. This
represents a shift in peak Compton energy of more than five orders of
magnitude. Possible interpretations are discussed, but we lack the
instantaneous sensitivity with Fermi to probe the underlying physics.
