  Within the Local Potential Approximation to Wilson's, or Polchinski's, exact
renormalization group, and for general spacetime dimension, we construct a
function, c, of the coupling constants; it has the property that (for unitary
theories) it decreases monotonically along flows, and is stationary only at
fixed points ---where it `counts degrees of freedom', i.e. is extensive,
counting one for each Gaussian scalar. Furthermore, by choosing restrictions to
some sub-manifold of coupling constant space, we arrive at a very promising
variational approximation method.
