By what criteria can one decide which of a person's countless beliefs are primitive? The essential factor is that they are taken for granted: a person's primitive beliefs represent the basic truths he holds about physical reality, social reality, and himself and his own nature. Like all beliefs, conscious or unconscious, they have a personal aspect: they are rooted in the individual's experience and in the evidence of his senses. Like all beliefs, they also have a social aspect: with regard to every belief a person forms, he also forms some notion of how many other people have the experience and the knowledge necessary to share it with him, and of how close the agreement is among this group. Unlike other beliefs, however, primitive beliefs are normally not open to discussion or controversy. Either they do not come up in conversation because everyone shares them and everyone takes them for granted, or, if they do come up, they are virtually unassailable by outside forces. The criterion of social support is totally rejected; it is as if the individual said: "Nobody else could possibly know or have experienced what I have." Or, to quote a popular refrain: "Nobody knows the trouble I've seen."
 A person's primitive beliefs thus lie at the very core of his total system of beliefs, and they represent the subsystem in which he has the heaviest emotional commitment.

Milton Rokeach