Abstract
Disorientation is not a uniform phenomenon and does not always follow the same pattern. Its pattern varies with its causes. Three varieties may be recognized. (1) The disorientation of toxic delirium. This is the best known variety. (2) The disorientation seen in some cases of schizophrenia. (3) That seen in some cases of brain tumour and other organic brain disease. The three varieties are all different, and the object of this paper is to consider why.