Ontology (of an algorithm or a mental state)

Two very general positions can be taken towards some posited entity - either algorithm/program or (the more frequently used) mental states:

1. Realist: accept it is a real existent entity. So propositional attitudes (see sec. ) actually exist. In the Standard Realist Position, beliefs and desires are internal states of the organism - each token of a propositional attitude is identifiable with a token of a state of the central nervous system.

   This is apparently the majority view: functionalism with danger of dualism?

2. Anti-Realist: argue that it lacks substantial existence (is such a view necessitated by Materialism?)

   The anti-realist position has two forms:

   1. Eliminativism: the entity lacks existence so should be eliminated from our discourse (re: propositional attitudes - eg. Churchland) (Eliminative Materialism in POM)

   2. Instrumentalism: talk of non-existent entities, while strictly false, may nevertheless be of practical value (Eg. Dennett). May later be replaced by processes with a better claim on reality. (Close to Methodological Dualism in POM)

      A very weak version: Having a belief is akin to, say, being immoral, having style, being talented, "would make a good wife", etc. - judgements that are of some value but could also easily be unreliable.

At a commonsense level, most people probably hold all three positions depending on the entities under examination, as exemplified by the following position of most contemporary analytic philosophers:

• Realist about matter (physical sciences)

• Instrumentalist about attribution of intentional states to computers (social sciences)

• Eliminativist concerning spiritual possession (superstition)