Summary: DENNETT DEFENDS THE IDEA THAT WHEN WE EXPLAIN SOMEONE'S BEHAVIOUR IN TERMS OF BELIEF AND DESIRES WE ARE NOT INVOKING INTERNAL STATES. WE ARE INVOKING THEORETICAL CONSTRUCTS WHICH HAVE BEEN ELABORATED BECAUSE OF THEIR EXPLANATORY POWER.
Summary: ORDINARILY WE USE 'BELIEF+DESIRE' EXPLANATIONS OF HUMAN BEHAVIOUR
In explaining our own behaviour and the behaviour of others in ordinary life the notion of a belief figures prominently. If we think of the brain as a computer, how are we to think of belief? Daniel Dennett (in 'True Believers', anyway) says beliefs are theoretical constructs.
To help us predict the behaviour of others we have developed a theory: folk psychology.
Folk psychology explains almost all human behaviour in terms of belief and desire.
The pattern is: we believe such and such; we want such and such; this leads us to do such and such.
Dennett says you don't have to think of a belief as something that is there in the brain - or in the mind - prior to the behaviour.
What is his alternative? Beliefs (and desires) are 'constructs': useful - instrumental - in the very successful theory we have developed for explaining human behaviour.
The concepts of belief and desire do their work, play their role in helping us predict behaviour accurately, quite irrespective of what events or what states may or may not be inside the person.
The advantage of Dennett's strategy is that it bypasses the traditional impasse that concentrating on consciousness gets us into.