  The angle $\psi$ between a planet's orbital axis and the spin axis of its
parent star is an important diagnostic of planet formation, migration, and
tidal evolution. We seek empirical constraints on $\psi$ by measuring the
stellar inclination $i_{\rm s}$ via asteroseismology for an ensemble of 25
solar-type hosts observed with NASA's Kepler satellite. Our results for $i_{\rm
s}$ are consistent with alignment at the 2-$\sigma$ level for all stars in the
sample, meaning that the system surrounding the red-giant star Kepler-56
remains as the only unambiguous misaligned multiple-planet system detected to
date. The availability of a measurement of the projected spin-orbit angle
$\lambda$ for two of the systems allows us to estimate $\psi$. We find that the
orbit of the hot-Jupiter HAT-P-7b is likely to be retrograde
($\psi=116.4^{+30.2}_{-14.7}\:{\rm deg}$), whereas that of Kepler-25c seems to
be well aligned with the stellar spin axis ($\psi=12.6^{+6.7}_{-11.0}\:{\rm
deg}$). While the latter result is in apparent contradiction with a statement
made previously in the literature that the multi-transiting system Kepler-25 is
misaligned, we show that the results are consistent, given the large associated
uncertainties. Finally, we perform a hierarchical Bayesian analysis based on
the asteroseismic sample in order to recover the underlying distribution of
$\psi$. The ensemble analysis suggests that the directions of the stellar spin
and planetary orbital axes are correlated, as conveyed by a tendency of the
host stars to display large inclination values.
