  New and rather controversial observations hint that the fine structure
constant \alpha may have been smaller in the early universe, suggesting that
some of the fundamental ``constants'' of physics may be dynamical. In a recent
paper, Davies, Davis, and Lineweaver have argued that black hole thermodynamics
favors theories in which the speed of light c decreases with time, and
disfavors those in which the fundamental electric charge e increases. We show
that when one considers the full thermal environment of a black hole, no such
conclusion can be drawn: thermodynamics is consistent with an increase in
\alpha whether it comes from a decrease in c, an increase in e, or a
combination of the two.
