We left off our story in early May 2007, (and that essay was mostly written that fall), when, in the aftermath of the French presidential election I first became fully convinced that people existed whose genuinely held ends I did not consider ends. Shortly thereafter Michael Ignatieff delivered the Isaiah Berlin Lecture at Wolfson College Oxford. (It is a measure of the significance of that speech that a reasonably extensive Google search has so far failed to find a transcript, or even a definite date, in part no doubt, because subsequent events would make a Michael Ignatieff lecture on political judgement vaguely embarrassing.) This was my first introduction to Isaiah Berlin, in whose tradition I mostly place myself, though I think the major theme of his work, the justification of a liberal pluralist order, is basically a failure. In any case I would like to start with one of Berlin’s definition of Politics:
Since men are beings made by nature to live in communities, their communal purposes are the ultimate values from which the rest are derived, or with which their ends as individuals are identified. Politics – the art of living in a polis – is not an activity which can be dispensed with by those who prefer private life : it is not like seafaring or sculpture which those who do not wish to do so need not undertake. Political conduct is intrinsic to being a human being at a certain stage of civilization, and what it demands is intrinsic to living a successful human life – Isaiah Berlin, The Originality of Machiavelli, 
So what does the art of living in a polis entail? To my understanding, it is the attempt to make the norms and institutions which structure our lives compatible with our ends, that is, reflective of our values. These kind of structures surround us with powerful incentives, such that generally it is only possible for a person to live contrary to prevailing norms, standards and institutions with effort and attention, both of which are limited quantities. Our understanding of willpower is nascent, however a key early finding is that people, by and large, work unconsciously, and conscious decisions deplete a limited reservoir of ability to override our unconscious desires. The key to living a life compatible with your values is to minimize the number of decisions that you need to make consciously. Since you will, as a practical manner, only physically be able to dissent from the prevailing Welterschauung of your community on a limited number of issues, tragedy may only be avoided where it is possible to surround yourself with structures that make living your values effortless. The full realization of your values may only be lived in community with people who share them.
Now you were born into a society with existing structures and norms, which embody within them certain trade-offs: between positive and negative liberties, between work and leisure, between individual and corporate ends and so on. What you cannot know a priori, and almost certainly cannot ever know with any degree of completeness, is which trade-offs are actually being embodied in any given structure. Structures, even considered in isolation, are often multivalent, and when interacting with other structures and norms it can quickly become practically impossible to fully specify everything that a given structure does. Thus even if you know what kind of life you would like to live, there is no way, on your own, to determine what kind of structures and norms would best provide a stable equilibrium that allows that kind of life, or even if such an equilibrium exists, much less to find a way to that life from where you are.
However, while it is impossible for an individual to know all of that, it is often possible for a single person to determine, with reasonable accuracy, the way that a certain interaction makes certain trade-offs. It is therefore possible for a group of people, none of whom know the entirety of any particular institution, to determine collectively what kind of trade-offs and values that it embodies. And a large group of people, none of whom know any constituent institution in detail, may be able to determine a basically coherent vision of what a good society looks like. It is therefore necessary, for a person to live their values, to find a group of people who share them, and to a great extent to defer to that group. However this leaves us with a problem. It is often difficult to determine exactly what you yourself value, and the extent to which you will be willing to make certain trade-offs can look very different depending on how those trade-offs are framed. It is not uncommon to find that a trade-off you though would make ahead of time suddenly seem unappealing when the time comes to actually make that decision. If you are opaque, even to yourself, can you, with substantially less knowledge, determine what someone else values? What a group values?