madness and the process of going mad comprehensible. In this, with case studies of schizophrenic patients, he succeeds brilliantly, but he does more: through a vision of sanity and madness as 'degrees of conjunction and disjunction between two persons where the one is sane by common consent' he offers a rich existential analysis of personal alienation.

The outsider, estranged from himself and society, cannot experience either himself or others as 'real'. He invents a false self and with it he confronts both the outside world and his own despair. The disintegration of his real self keeps pace with the growing unreality of his false self until, in the extremes of schizophrenic breakdown, the whole personality disintegrates.