“That our opinion gives value to things is seen by the many things that we do not think about even to appraise them, preferring to think about ourselves instead. We consider neither their qualities not their uses, but only the cost of us getting them, as if that were some part of their substance; and we call value in them not what they bring, but what we bring to them. At which point I note that we are great economizers of our expenditure. According as it weighs, it serves by the very fact that it weighs. Our opinion never lets it run at a false valuation. Purchase gives value to the diamond, and difficulty to virtue, and pain to piety, and harshness to medicine.” (I:14, 43, Frame)