  Recent theorems of Dubickas and Mossinghoff use auxiliary polynomials to give
lower bounds on the Weil height of an algebraic number $\alpha$ under certain
assumptions on $\alpha$. We prove a theorem which introduces an auxiliary
polynomial for giving lower bounds on the height of any algebraic number. Our
theorem contains, as corollaries, a slight generalization of the above results
as well as some new lower bounds in other special cases.
