An attempt to describe the social good in detail seems to carry with it an implied willingness to impose this good, independently of observed or prospective agreement among persons. By contrast, my natural proclivity as an economist is to place ultimate value on process or procedure, and by implication to define as “good” that which emerges from agreement among free men.
I add here that, unlike Jim, I regard spontaneous agreement  – agreements made at ‘micro’ levels, in local situations, and with no intention by individuals to participate in any system for making law for the larger society – as being a far-superior process of law-making than is deliberative democracy. Law made by deliberation and imposed consciously on a group of people is more properly called “legislation” and is less likely to be informed by the – and to allow individuals to be guided by their – ‘knowledge of the particular circumstances of time and place.’
Legal central planning is no more likely to work well than is economic central planning. The process of making law decentrally and spontaneously (no less than the process of making resource-allocation decisions decentrally and spontaneously) is far superior to making ‘law’ – i.e., legislating – centrally and consciously. (Such consciously designed and centrally, top-down imposed legislation is also far more likely than is spontaneous law to serve special interest groups at the expense of the general public.)