"The small and cheerful book at hand, by a well-known researcher on the brain from Tübingen, has exploited the virtues of the style with unprecedented consistency, originality and aptness. His thought experiments are not analytic efforts to extract what principles lie behind an imagined observation but are instead synthetic constructions. They are little toys of the mind, devised out of simple if fictional components, entirely functionally described.... [A] crisp, cogent book full of intellectual delights."
- Philip Morrison, Scientific American