Consensus is a decision making process that works creatively to include all persons making the decision. It is the most powerful decision process as all members agree to the final decision. This is truly radical democracy as all participants have a direct voice and veto power.

Consensus can work with groups as small as 5, groups of 300, or even over 500,000 people. Within a small group consensus tends to be more simple if all the group participants are kept abreast of each other's activities and all the factors of the decision. Within groups of 300 or so, consensus takes fractally differents shapes: the group might have a single faciliator, and the 300 members may be arranged into mini-groups of 5 using consensus and with one spokesperson who speaks in the larger group.

Or consensus can work with territories such as lower Mexico (Oaxaca and Chiapas). The Zapatistas answer to a public control called "la consulta". This group - comprised of all men, women and children 12 and over - meets in local meetings where discussion is held and all the members make the final decision. This process worked in declaring war on the Mexican government and held through the intitial attempts to diffuse the situation with offers of "peace talks" from the Government.

In short consensus takes into account and validates each participant. Everyone gets the opportunity to voice their opinion, or block a proposal if they feel strongly enough about a decision.

Note: Can't remeber where I found this document but I know the authors won't mind.