Perfect being theology is the attempt to decide questions about the nature of God by employing the Anselmian formula that God is the greatest possible being. One form of perfect being theology—recently defended by Brian Leftow in God and Necessity—holds that we can decide between incompatible claims that God is F and that God is not F by asking which claim would confer more greatness on God, and then using the formula that God is the greatest possible being to rule (...) out the one which confers less greatness on God. This paper argues that this form of argument, while intuitively quite plausible, does not work. (shrink)