  We study the Josephson effect through a magnetic molecule with anisotropic
properties. Performing calculations in the tunneling regime, we show that the
exchange coupling between the electron spin on the molecule and the molecular
spin can trigger a transition from the $\pi$ state to the 0 state, and we study
how the spin anisotropy affects this transition. We show that the behavior of
the critical current as a function of an external magnetic field can give
access to valuable information about the spin anisotropy of the molecule.
