Editing Consensus theory of truth (section)

==Varieties of consensus==
===Consensus gentium===

An ancient criterion of truth, the ''[[consensus gentium]]'' ([[Latin language|Latin]] for ''agreement of the people''), states "that which is universal among men carries the weight of truth" (Ferm, 64).  A number of consensus theories of truth are based on variations of this principle.  In some criteria the notion of universal consent is taken strictly, while others qualify the terms of consensus in various ways.  There are versions of consensus theory in which the specific population weighing in on a given question, the proportion of the population required for consent, and the period of time needed to declare consensus vary from the classical norm.

===Consensus as a regulative ideal===

A ''[[descriptive theory]]'' is one that tells how things are, while a ''[[normative theory]]'' tells how things ought to be.  Expressed in practical terms, a normative theory, more properly called a ''[[policy]]'', tells agents how they ought to act.  A policy can be an absolute imperative, telling agents how they ought to act in any case, or it can be a contingent directive, telling agents how they ought to act ''if'' they want to achieve a particular goal.  A policy is frequently stated in the form of a piece of advice called a ''[[heuristic]]'', a ''[[maxim (philosophy)|maxim]]'', a ''[[norm (philosophy)|norm]]'', a ''[[:wikt:rule|rule]]'', a ''[[slogan]]'', and so on.  Other names for a policy are a ''recommendation'' and a ''[[regulative principle]]''.

A regulative ideal can be expressed in the form of a description, but what it describes is an ideal state of affairs, a condition of being that constitutes its aim, end, goal, intention, or objective.  It is not the usual case for the actual case to be the ideal case, or else there would hardly be much call for a policy aimed at achieving an ideal.

Corresponding to the distinction between actual conditions and ideal conditions there is a distinction between actual consensus and ideal consensus.  A theory of truth founded on a notion of actual consensus is a very different thing from a theory of truth founded on a notion of ideal consensus.  Moreover, an ideal consensus may be ideal in several different ways.  The state of consensus may be ideal in its own nature, conceived in the matrix of actual experience by way of intellectual operations like abstraction, extrapolation, and limit formation.  Or the conditions under which the consensus is conceived to be possible may be formulated as idealizations of actual conditions.  A very common type of ideal consensus theory refers to a community that is an idealization of actual communities in one or more respects.