SIFA 2006

Brains, Persons, and Society *** ABSTRACTS
Cervelli, Persone e Società ***ABSTRACTS

Fabio Paglieri
University of Siena / ISTC-CNR Roma, Italy

Ryan McKay
The Center for Cognitive Studies, Tufts University, USA

Believing without accepting: the doxastic conception of delusions revisited

Recently there has been considerable philosophical debate on the true nature of pathological delusions, both monothematic (e.g., Capgras, Cotard, Fregoli delusion) and polythematic, as those frequently associated with schizophrenia. The standard clinical definition, according to which delusions are false, unjustified beliefs, has been challenged by several authors, and some alternative proposals emerged. In this paper we argue that this discussion would benefit from taking into account the conceptual distinction between beliefs and acceptances, first introduced in the philosophy of action and epistemology. We show how this distinction reveals the inadequacy of the main criticism mounted against doxastic accounts of delusions, i.e. behavioural inertia, and how it serves to address some important problems on the nature of delusional beliefs.

Competing accounts of delusions

We begin by summarizing four alternative positions on the nature of delusions:

· belief thesis, or doxastic account (1, 2);

· meta-cognitive thesis (12, 13, 14, 26);

· no-content thesis, i.e. expressivist / non-assertoric account (4, 20);

· loss-of-understanding thesis (10, 15).

Then we review the main criticisms raised against the doxastic account, i.e. the idea that delusions constitute genuine instances of belief:

· lack of pragmatic commitment (5, 12, 19, 20, 24);

· lack of affective commitment (24);

· inability to provide convincing reasons (10, 19);

· lack of integration with other beliefs (8, 9, 21, 33).

These features are taken to constitute prima facie evidence that delusions are not beliefs, since each of the missing characteristics is supposed to be an essential property of belief. In what follows, we focus on lack of pragmatic commitment, to show how the distinction between belief and acceptance dissolves this line of attack against the doxastic account of delusions.

Acceptance and belief

We introduce the technical distinction between belief and acceptance, concentrating on the seminal contributions made in 7, 11, and 25. We focus on the opposition between belief and pragmatic acceptance, as contrasted with acceptance as assent (16, 28): thus we emphasize that acceptance is linked with practical usage of a mental representation in connection with an action (the accepted proposition is treated as if it was true: pragmatic function), while belief in contrast concerns a subjective picture of how we hold things to be, which is meant to provide a veridical representation of the world (alethic function). On this ground, and contra other authors (16, 25, 32), we defend the idea that both instances of belief without acceptance and acceptance without belief are possible and, under the appropriate circumstances, rational.

Believing without accepting in delusions

For a theory of delusions, the significance of separating belief from acceptance is twofold: (i) it undermines the lack-of-pragmatic-commitment objection; (ii) it provides a new conceptual framework to describe and analyze puzzling features of delusions, e.g. the fact that while some delusions remain behaviourally inert, others find expression in concrete actions.

The evidence on the frequent lack of pragmatic commitment in delusions is robust (6, 19, 22, 31, 34). We do not contest these data – in fact, we do not need to, in order to defend the doxastic account of delusions. The distinction between belief and acceptance suggests that lack of pragmatic commitment constitutes evidence that certain delusions are not acceptances – but it has little bearing in assessong whether these delusions are beliefs. Thus, this criticism against doxastic accounts of delusions is misguided, and owes to a confusion between different functional roles of mental representation.

Believing without accepting as a preventive measure

Although behavioural inertia is widespread, it is not an unvarying feature of delusional belief. Thus, whereas some patients do not engage in delusion-related actions, others do act on their delusional beliefs, sometimes with tragic consequences (33). In fact, delusion-generated behaviour is more common than is often thought (2), and has been reported in a variety of specific delusional themes, e.g. erotomania (22), Capgras syndrome (17) and Cotard syndrome (34).

We try to frame this observation within our hypothesis of behaviourally inert delusions as instances of belief without acceptance. Our tentative suggestion on this point revolves around the pragmatic nature of acceptance: we surmise that, whenever deluded subjects have reasons to expect negative outcome from their delusion-related actions, they refrain from performing such actions – not because they do not believe in their delusions, but because they are aware of possible unfavourable consequences, thus lacking pragmatic reasons to act on them. We detail this suggestion, discussing both its implications (3, 18, 23, 27, 29, 30), and its plausibility in light of some empirical evidence on Capgras syndrome (17, 33) and erotomania (22).