Hermann Rorschach originally conceived of his test as a diagnostic instrument. It has been the practice for psychologists to use the Rorschach in an attempt to establish a psychiatric diagnosis.
Psychiatric disorders are not discrete illnesses. The Rorschach enables us to analyze the nature of psychiatric conditions and, in many instances, draw inferences about their causes. In order to do this, however, it is necessary to have a theory of personality that links together phenomena in a causal sequence. Through this test we are able to draw inferences about the underlying structure of the subject's personality, his or her enduring ways of attending to and organizing the world, his or her experience of affect, of self and other, as well as the personality dynamics underlying this structure. There are several levels of data within a Rorschach protocol that can be analyzed in order to provide the kind of diagnosis.
The most accurate diagnostic formulations are those that take into account both manifest phenomenaóthat is observable behavior and symptomatologyóand underlying structureói.e., character. Thus, by integrating findings from the Rorschach and other assessment instruments such as the TAT with data from interview and observation, we can arrive at a diagnostic formulation that captures the fullness of the individual as a person. Moreover, such a formulation is likely to involve propositions that are more clinically useful than mere categorical diagnosis.