Abstract
This paper explores the two-factor theoretical model currently widely used to provide an explanatory analysis of the delusions that regularly accompany neurological disease or damage. The model hypothesizes a combination of an experiential factor – a strange or untoward experience – and a cognitive factor, such as an impairment of reasoning. The two-factor model has been devised formonothematicdelusions that are usually manifested in a single, implausible idea. These have to be distinguished from the more elaborated,polythematicdelusions that are found in psychiatry. Psychiatric delusions exceed neurological ones in frequency and, often, semantic complexity. This text offers a preliminary clarification of underlying assumptions about the breadth, terminology and presuppositions of two-factor theorizing, exploring its potential application to psychiatric delusions.