  The emergent area of gravitational wave astronomy promises to provide
revolutionary discoveries in the areas of astrophysics, cosmology, and
fundamental physics. One of the most exciting possibilities is to use
gravitational-wave observations to test alternative theories of gravity. In
this contribution we describe how to use observations of extreme-mass-ratio
inspirals by the future Laser Interferometer Space Antenna to test a particular
class of theories: Chern-Simons modified gravity.
