John Wooden

To ask questions can become the laziest and wobbliest occupation of a mind, but when you must yourself answer the problem that you have posed, you will meditate your question with care and frame it with precision.

Though builders may build, in the main they follow the plans of architects. Teachers teach, but they must have a text. Politicians govern, but only upon the flow of commentary that raises them up or casts them down.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.