What is it that brings the hero or heroine of a Tragedy so inexorably to catastrophe? The first people to consciously ask this question were the ancient Greeks; and they had no doubt that all the great tragic figures in their mythology had something profoundly in common. They called it hubris, which we usually interpret as a form of overweaning pride, a reckless arrogance. But the literal derivation of hubris was from the word hyper, meaning 'over'. It meant a 'stepping over the bounds', a defiance of the cosmic order, that state of perfect balance which ultimately holds the universe together (characterised in the motto 'nothing in excess', written up over the temple of Apollo...). By the rule of that same balance, anything which disturbed it would eventually meet with a violent shock as the state of balance and order was restored. The inevitable consequence of hubris was nemesis, from the root nemein, to 'allot a due portion', the same root from which sprang nomos, 'law'. Literally, nemesis was the 'due portion' required to restore the equilibrium of the cosmic order when it had been unbalanced by an act of hubris.For those people reading this who haven't got it yet(!), in a footnote, Booker points out that the word for an arrow deviating in this way is translated as "sin"! In other words "sin" is the reason that the central characters of tragedies are unable to achieve their goal. To cut an incredibly long analysis short, Booker makes the point that all the seven basic plots are the same story - a person moving from a state of incompleteness to a state of completeness, with the exception of Tragedy, where the person fails to do so.
But the Greeks went further than this in providing a general answer to the question of why the tragic hero must come to ultimate disaster. As Aristotle put it in a famous passage in the Poetics, there was a specific reason why the heroes and heroines of tragedy ... should fall prey to hubris in the first place. The essence of a tragic hero or heroine ... is that they must not be shown as wholly good or bad, but that they must be shown as being brought from 'prosperity to misery' through some 'fatal flaw'. And the Greek for this was hamartia, which means literally 'missing the mark', as an arrow fails to reach its target. [Switched on Christians will now see where this is going, and why my jaw hit my chest when I read it in a non-Christian book analysing the role of narrative!] The fatal flaw in the tragic hero or heroine is that deficiency in their character or awareness which prevents them from 'reaching the goal'.
In other words, the very nature of the 'fatal flaw' in these central figures of tragedy is that it is something which renders them unable to 'succeed'... The essence of the tragic hero or heroine, in short, is that they are held back by some fatal flaw or weakness from reaching that state of perfect balance which is presented by stories as the supreme goal of human existence. They are doomed to fall short of the goal because in some way they are stuck in a state of incompleteness or immaturity.
"The Seven Basic Plots", Christopher Booker, p.329-330
So what is the role of narrative, if this is the dire warning which it presents people with - although this warning is already embedded in humanity's collective psyche, since the reason the plots work is because we recognise their significance. Booker applies this (I believe - this is really addressed properly in part four, which I still haven't got to) in social terms - the "complete" objective for a person he has in mind is basically when a person establishes themselves in a proper, non-egotistical relationship, taking their proper role in society and the world.
But he is writing with a presupposition that there is no external absolute - that the social order is the highest good. What happens when you consider this from within a Christian framework? Here, we can see the real problem of sin - that it holds people back not only from a proper place in human society, but from a proper relationship with God as well. God said to Adam and Eve that their sin not only had an impact on them as individuals (death) and in their relationship with him, but also it has an impact on their relationships with each other, and with the world, and in their own psyches. So the Christian framework adds a huge extra dimension to the threat of sin. The tragedy of sin preventing us from achieving completeness or maturity is that it brings with it the threat of destruction. The Christian hope is that the tragedy that we face if we can't deal with this problem of sin can be averted through the gospel - through the light and wisdom that Jesus brought into the world. And as with the other plots, the resolution of the problem of sin is not just personal, but it is cosmic in scope. There is "rejoicing in heaven" when a person turns away from their sin!