“If a thing is to have a market value, it must be detachable or alienable so that it can be put on the scale and compared. I mean this in a particular sense: we who do the valuation must be able to stand apart from the thing we are pricing. We have to be able to conceive of separating ourselves from it. I may be fond of my wristwatch but I can put a value on it because I can imagine parting with it. But my heart has no market value (at least not to me!), for to detach it is inconceivable. (I address below the interesting question of value in relation to body organs used for transplant.) We feel it inappropriate, even rude, to be asked to evaluate in certain situations.”