Discourses, "On the Power of Speaking" (§2)

“Man, be neither ungrateful for these gifts nor yet forget the things which are superior to them. But indeed for the power of seeing and hearing, and indeed for life itself, and for the things which contribute to support it, for the fruits which are dry, and for wine and oil give thanks to God: but remember that he has given you something else better than all these, I mean the power of using them, proving them, and estimating the value of each.”