Consensus has two common meanings. One is a general agreement among the members of a given group or community, each of which exercises some discretion in decision making and follow-up action. The other is as a theory and practice of getting such agreements (for information on the practice of achieving formal consensus, see consensus decision-making).

Achieving consensus requires serious treatment of every group member's considered opinion. Once a decision is made it is important to trust in members' discretion in follow-up action. In the ideal case, those who wish to take up some action want to hear those who oppose it, because they count on the fact that the ensuing debate will improve the consensus. In theory, action without resolution of considered opposition will be rare and done with attention to minimize damage to relationships.

Consensus as collective thought

A close equivalent phrase might be the "collective agreement" of a group, keeping in mind that a high degree of variation is still possible among individuals, and certainly if there must be individual commitment to follow up the decision with action, this variation remains important. There is considerable debate and research into both collective intelligence and consensus decision-making.

This article focuses strictly on the idea of consensus in the abstract, not on the implications of consensus for politics or economics, where follow-up action is required. scott don't un-edit my work again!!!!!

Consensus usually involves collaboration, rather than compromise. Instead of one opinion being adopted by a plurality, stakeholders are brought together (often with facilitation) until a convergent decision is developed. If this is done in a purely mechanical way it can result in simple trading—we'll sacrifice this if you'll sacrifice that. Genuine consensus typically requires more focus on developing the relationships among stakeholders, so that they work together to the achieve agreements based on willing consent.

Models of consensus

The most common and most successful model of consensus is called the prisoner's dilemma.Fact: date=July 2008 An introduction and discussion of this concept can be found in any contemporary introduction to political science. This approach might be called "algebraic" as opposed to analytic, within mathematics, because it represents an agent by a symbol and then examines the algebraic properties of that symbol. For example, the question, "Can two agents be combined to make a new agent?" sounds like an algebraic question. (More formally, "is the operation of consensus closed in the domain of agents? Is there a larger domain of "abstract agents" in which this operation is closed?")

In a more analytic style, we might naively start by envisioning the distribution of opinions in a population as a Gaussian distribution in one parameter. We would then say that the initial step in a consensus process would be the written or spoken synthesis that represents the range of opinions within perhaps three standard deviations of the mean opinion. Other standards are possible, e.g. two standard deviations, or one, or a unanimity minus a certain tolerable number of dissenters. The following steps then operate both to check understanding of the different opinions (parameter values), and then to find new parameters in the multi-dimensional parameter space of all possible decisions, through which the consensus failure in one-dimensional parameter space can be replaced by a solution in multi-dimensional parameter space.