In this paper I discuss an issue concerning how faith ought to be held. Traditionally there have been those who contended that faith should be held with full certainty, with great firmness. John Calvin is an example. John Locke offered both epistemological and pragmatic considerations in favor of the view that faith should be held with distinctly less than maximal firmness. He proposed a Principle of Proportionality. I assess the tenability of Locke’s proposal-while also suggesting that Calvin’s position is different from whaton first reading it would appear to be. It is not straightforwardly in conflict with Locke’s position.