Consensus reality is an approach to answering the philosophical question "What is real?" It gives a practical answer: reality is either what exists, or what we can agree seems to exist.[citation needed]
The process has been (perhaps loosely and a bit imprecisely) characterised as "when enough people think something is true, it... takes on a life of its own".[citation needed] The term is usually used disparagingly as by implication it may mean little more than "what a group or culture chooses to believe", and may bear little or no relationship to any "true reality", and, indeed, challenges the notion of "true reality".
The difficulty with the question stems from the concern that human beings do not in fact fully understand or agree upon the nature of knowledge or knowing, and therefore (it is often argued) it is not possible to be certain beyond doubt what is real. Accordingly, this line of logic concludes, we cannot in fact be sure beyond doubt about the nature of reality. We can, however, seek to obtain some form of consensus, with others, of what is real. We can use this consensus as a pragmatic guide, either on the assumption that it seems to approximate some kind of valid reality, or simply because it is more "practical" than perceived alternatives. Consensus reality therefore refers to the agreed-upon concepts of reality which people in the world, or a culture or group, believe are real (or treat as real), usually based upon their common experiences as they believe them to be; anyone who does not agree with these is sometimes stated to be "in effect... living in a different world."