Frank Lloyd Wright once said that inferior minds work by comparison while superior minds work by analogy. As an aphorism this matches Buckminster Fuller's better known one about the task of design being to do more with less, so that even if resources dwindle, there can still be more for everyone, but in either case, the use of analogy to tease out technology is a gift from the gods because it really works.
Take clocks for example. They started out as sundials rooted to the spot; then they got their solar mechanism so they could be mounted anywhere they could be seen; then their mechanism shrank down to the size of a pocket watch; then a wristwatch; then something so small that its flashing digits can be fixed to anything from a credit card to a car.
Tales of miniaturisation like this chase each other down the centuries: the development and extinction of the camera; the weight of coinage; the output of an engine; the mass of a bridge structure; the cost of a photovoltaic cell; the size of a mobile phone; and so on, until after a time it all becomes too easy.
That is when the analogists' task becomes to find out the exact change points in this process of evolution, not just glossing over them or, better yet, to actually predict these major shifts on the basis of data taken from completely different fields.
In short, that is when you use the methods of meteorology and market research to predict the future of structures and machines.
To show how analogue aphorisms can produce answers where nothing else can, let us have the past predict the future by means of an analogy so arcane that it may never have been explored before - the decline and extinction of the battleship as a model for the fate of tall buildings.
We can start with a passage from David Howarth's Sovereign of the Seas, a history of British sea power, published in 1974: 'The affairs of nations are often guided by sentiment rather than logic, and battleships in every age were wonderful creations.
They had a fierce feline beauty like a tiger, 'a fearful symmetry'; and even when they proved impractical, their beauty may have had some martial value in itself, to give confidence to a nation that possessed them, and give pause to a nation that did not.'
Now consider the same passage with the word 'battleships' replaced by 'tall buildings': 'The affairs of nations are often guided by sentiment rather than logic, and tall buildings in every age were wonderful creations. They had a fierce feline beauty like a tiger, 'a fearful symmetry'; and even when they proved impractical, their beauty may have had some political value in itself, to give confidence to a nation that possessed them, and give pause to a nation that did not.'
Clearly the sense of the passage is not destroyed by the substitution, so let us assume that the analogy is not either.
Here is another passage: 'So the great battleships survived, and the people took comfort from their existence, as they always had. But more and more of the strength of each battleship was being diverted to its own protection.'
Making the same substitution in this passage we have the following: 'So the tall buildings survived, and the people took comfort from their existence, as they always had. But more and more of the strength of each tall building was being diverted to its own protection.'
Once again the sense of the passage has not been destroyed by the substitution, but its message has become predictive. Now it is a harbinger of 11 September 2001.