This chapter explores the relevancy of Aron Gurwitsch's phenomenological analysis of the field of consciousness—in particular his distinction between theme, thematic field, and margin of awareness— for understanding certain abnormalities of consciousness and cognition in schizophrenia. Alterations in the organization of the field of consciousness have long been recognized as a key feature of the schizophrenic condition. It has been difficult, however, to specify these aberrations very precisely, or to capture the nature of schizophrenic abnormalities in contrast with vaguely analogous abnormalities that are found in mania, dementia, and various neurological conditions. Traditional theories of attentional dysfunction have been found to be inadequate. I argue that (A) the distinctively schizophrenic alterations of perception, thought, and language demonstrated in recent research pertain especially to what Gurwitsch calls the "thematic field" and (B) disturbances involving the margin or the theme may best be viewed as secondary consequences of this disturbance of the thematic field. I discuss a number of abnormalities of schizophrenic cognition, including perplexity, dissemination (proliferation of meanings), fragmentation, perspectival slippage, and certain quasi-surrealistic ways of experiencing what is familiar or strange.