Recycling your opinion in seven variations only

SOME years ago some clever person came up with the notion that there are only seven types of plot, an idea that was extended into the field of comedy.

Nowadays, it’s not uncommon to meet a comic who will nod sagely and tell you that there are only seven types of joke. Usually, they don’t know what they are, but that’s not the point: the thrust of what they are saying is that it is exceptionally difficult to be original within a form which is seemingly limited by the physics of humour; yet they’ve managed it nonetheless.

But if creativity in these fields is limited, might the same strictures also apply to other forms of human thought?