What might have been

Possible worlds – the very phrase can set the speculative imagination alight. Leibniz suggested that this world was the best of all possible worlds. The suggestion has enraged some, bewildered many, satisfied some and set others to pondering. What is this idea of possible worlds?

Many works of narrative fiction, such as novels, films and even television programmes, describe possible worlds. Such worlds usually have some sort of internal consistency, or some sort of internal logic, even when they are quite unrealistic. Although realism is not always important, it can be. This is particularly so with the genre of historical novels and films. Works such as Pride and Prejudice and No Barrier are highly realistic and depend on a setting that is historically accurate. By contrast, some novels, and the films derived from them, such as The Lord of the Rings and Harry Potter and the Philosopher's Stone are works of sheer fantasy. Their setting is quite unlike the real world in crucial ways. They are valued just because they are not realistic. But there is an internal logic to the possible worlds described in these works.

In the television series Sliders there is explicit use of the idea of possible worlds. The series is built on the idea of possible worlds parallel to ours, worlds to which the heroes can “slide”. The heroes have their adventures in these possible worlds, in a different one each episode.