There is, indeed, nothing that man’s nature seeks more eagerly than to be flattered. Accordingly, when his nature becomes aware that its gifts are highly esteemed, it tends to be unduly credulous about them.
Institutes of the Christian Religion, Volumes 1 & 2, – ed. John T. McNeill, trans. Ford Lewis Battles, The Library of Christian Classics (Louisville, KY: Westminster John Knox Press, 2011), 242-243.