The domain of thought may be conceived of as a space occupied by no-things; the space occupied by a particular no-thing is marked by a sign such as the words “chair”, or “cat” or “point” or “dog”. The personality that is capable of tolerating a no-thing can make use of the no-thing, and so is able to make use of what people can now call thoughts. The “symptoms” as observed clinically can be represented “spatially” in this geometric scheme by points that belong to the projected transformation. The analyst must be able to detect signs of projective identification in a field which, relative to that which obtains in classical theory, is, as it were, multi-dimensional. The analytic situation requires greater width and depth than can be provided by a model from Euclidean space. Unless each term can be defined and used with accuracy misunderstandings multiply. Rigid definition would defeat the aim to provide an element unsaturated in the clinical experience.