The concept of insight into psychosis has received scant attention in the psychiatric literature. Drawing on sources such as phenomenology, clinical research and experimental psychology, it is proposed that insight is not an ‘all-or-none’ phenomenon but is composed of three distinct, overlapping dimensions, namely, the recognition that one has a mental illness, compliance with treatment, and the ability to relabel unusual mental events (delusions and hallucinations) as pathological. A scheme is proposed to standardise the assessment of insight to assist further research.