Predictions are uttered by prophets (free of charge); by clairvoyants (who usually charge a fee, and are therefore more honored in their day than prophets); and by futurologists (salaried). Prediction is the business of prophets, clairvoyants, and futurologists. It is not the business of novelists. A novelist's business is lying.

Introduction (p. xii) - Hainish Cycle - The Left Hand of Darkness (1969)