The negative-positive dichotomy of schizophrenic symptoms and syndrome
s is the current version of ongoing attempts to subdivide the multifar
ious clinical manifestations of schizophrenia into more simple, homoge
neous classes. The theoretical background for the negative-positive di
stinction in Anglo-Saxon literature is not explicitly formulated, alth
ough it rests on a hidden conceptual framework, inspired by metaphysic
al evolutionary ideas of the functional organization of the mind, orig
inally proposed by Hughlin Jackson. Conceptual aspects and research ev
idence of this dichotomy are reviewed. Its validity seems doubtful bot
h on conceptual and empirical grounds. The phenomenological approach a
nd neural network models are introduced as a possible framework to stu
dy schizophrenic symptomatology.