I have just been to an excellent talk by Angie Hobbs (University of Warwick) on the ethics of money. The talk made an eloquent case for the involvement of all kinds of thinkers, including philosophers, historians, psychologists and anthropologists, in debates on the financial system. I think that is right. Moreover, the hard-pressed philosophy lecturers who need to build up their CVs with technical papers should not be seduced into thinking that this would be second-rate philosophy, because not sufficiently technical. It is what Plato and Aristotle did, and it needs re-doing in modern circumstances. Correspondingly, it needs to be given sufficient credit by those who appraise university departments and hand out the money.
One of Angie's central points was that if we are going to get money, banking and the like right, we have to be clear about what we want on a broader scale: what kind of life, what kind of society, and so on. In particular, we can miss a lot if we think that everything is even potentially reducible to monetary terms. On the other hand, there is a strong temptation to try to reduce everything to a common scale of value, because it makes decision-making easier.
She suggested that some important things were not quantifiable. I am not sure that we need to go that far, in order to accommodate the evident phenomenon that some decisions as to what to do are not mechanically computable. It could be that there are quantitative scales, or at worst orderings, for many goods, including cultural goods such as beauty and mental challenge. For example, if there is any sense to the notion of one kind of music being objectively better than another, then Mozart is better than the Beatles, even if one happens to prefer the Beatles. But the problem is that there are many scales, orthogonal to one another or otherwise incommensurable. So we can rate options along single scales. We can perhaps place options on indifference hyper-surfaces that cover a limited selection of scales, then use a production possibility hyper-plane to find a local optimum for the limited selection of scales. But we might still lack the means to find global optima, or even local optima across reasonably wide localities (a locality being defined as a set of scales).
This thought does not of course exclude the possibility that some goods are indeed absolutely non-quantifiable. There can be grounds for thinking that, apart from the fact that some decisions are not mechanically computable. But the optimist in me does not want to rule out quantification, or at worst ordering, in advance.
One thing of which I am convinced is that if something can be measured on a single scale, it cannot be the good for humanity. The utilitarianism of the modern proponents of the science of happiness is refuted as soon as they claim that human happiness is measurable on a one-dimensional scale. It is not just that we happen to be too complicated for one dimension. One-dimensional value would be unworthy of us. We need the space for irresoluble conflict, in order to be human.