Narrativium

The most common element on the disc, although not included in the list of the standard five: earth, fire, air, water and surprise. It ensures that everything runs properly as a story. For example, if a boy has two older brothers, chances are they will go on a quest. The first will be strong, and fail because of his stupidity, the second will be smart, and fail because of his frailty and the youngest brother will then have no choice but to go out, succeed and bring fame and fortune to his poor family. This phenomenon is also known as Narrative Causality. Dragons breathe fire not because they have asbestos lungs, but because that is what dragons do. Heroes only win when outnumbered, and things which have a one-in-a-million chance of succeeding often do so. The application of this phenomenon appears to be governed by some loosely formulated laws.

The Wizards have found that the Roundworld has no Narrativium at all, and are amazed that it can still function. Instead, Roundworld functions with quantum, also known as physics by its inhabitants.

Quotes mentioning Narrativium from Science of Discworld (I, II and III)

Our minds make stories, and stories make our minds. Each culture's Make-a-Human kit is built from stories, and maintained by stories. A story can be a rule for living according to one's culture, a useful survival trick, a clue to the grandeur of the universe, or a mental hypothesis about what might happen if we pursue a particular course. Stories map out the phase space of existence (II: 327).

The characteristic feature of narrativium is that it makes stories hang together. The human mind loves a good dose of narrativium. (I:64)

A little narrativium goes a long way: the simpler the story, the better you understand it. Storytelling is the opposite of reductionism: 26 letters and some rules of grammar are no story at all. (I: 93)

Narrativium is powerful stuff. We have always had a drive to paint stories on to the Universe. When humans first looked at the stars, which are great flaming suns an unimaginable distance away, they saw in amongst them giant bulls, dragons, and local heroes. This human trait doesn't affect what the rules say -- not much, anyway -- but it does determine which rules we are willing to contemplate in the first place. Moreover, the rules of the universe have to be able to produce everything that we humans observe, which introduce a kind of narrative imperative into science, too. Humans think in stories.... (I: 11)

Humans add narrativium to their world. They insist on interpreting the universe as if it's telling a story. This leads them to focus on facts that fit the story, while ignoring those that don't. (I:233)

...humans seem to need to project a kind of interior decoration on to the universe, so that they spend much of the time in a world of their own making. We seem --at least at the moment-- to need these things. Concepts like gods, truth and the soul appear to exist only in so far as humans consider them to do so... But they work some magic for us. They add narrativium to our culture. They bring pain, hope despair, and comfort. They wind up our elastic. Good or bad, they've made us into people. (I: 166)

Our children have been hearing stories since they recognized any words at all, and by three years old they are making up their own stories about what is happening around them. We are all impressed by their vocabulary skills, and by their acquisition of syntax and semantics; but we should also note how good they are at making narratives out of events. From about five years old, they get their parents to do things for them by placing those things in narrative context. And most of their games with peers have a context, within which stories are played out. The context they create is just like that of the animal and fairy stories we tell them. The parents don't instruct the child how to do this, nor do the children have to elicit the 'right' storytelling behaviours from their parents. This is an evolutionary complicity. It seems very natural --after all, we are Pan narrans-- that we tell stories to children, and that children and parents enjoy the activity. We learn about 'narrativium' very early in our development, and we use it and promote it for the whole of our lives. (II: 152)

Narrativium is not an element in the accepted sense. It is an attribute of every other element, thus turning them into, in an occult sense, molecules. Iron contains not just iron, but also the story of iron, the history of iron, the part of iron that ensures that it will continue to be iron and has an iron-like job to do, and is not for example, cheese. Without narrativium, the cosmos has no story, no purpose, no destination. (III: 1-2)

It looks like Ian Stewart and Jack Cohen are the source of the coinage Pan narrans, of which they say

We are not Homo sapiens, Wise Man. We are the third chimpanzee. What distinguishes us from the ordinary chimpanzee Pan troglodytes and the bonobo chimpanzee Pan paniscus, is something far more subtle than our enormous brain, three times as large as theirs in proportion to body weight. It is what that brain makes possible. And the most significant contribution that our large brain made to our approach to the universe was to endow us with the power of story. We are Pan narrans, the storytelling ape. (II: 325)

...if you understand the power of story, and learn to detect abuses of it, you might actually deserve the appellation Homo sapiens. (II: 330)