Criticism, a technique more familiar in the arts than in the sciences, concerns itself with the "how" rather than the "what" of things. Its objective is the form, the manner or mode of representation, as opposed to content.
In dealing with phenomena of infinite individual variation, such as the language used by schizophrenic patients, the identification of form, or style, can be used as a principle of unification. The syndrome of "concreteness," the syndrome of "ambiguity," the syndrome of "transformation into personal idiom" (illustrations given) identify styles characteristic and recurrent in this use of language.
Identification of these "styles" or manner of speaking, make an intelligible transition to the manner of thinking or modes of thought.
Criticism can evolve very flexible techniques for the investigation of mental operations as they appear in language. Proper criticism does not limit itself to normative standards, for
LORENZ M. Criticism as Approach to Schizophrenic Language. Arch Gen Psychiatry. 1963;9(3):235-245. doi:10.1001/archpsyc.1963.01720150045007