Human beings habitually understand themselves as agents. An agent is an individual with reasons for its behavior. Agents have goals (things they desire), and produce behavior which they believe will achieve those goals. Thus Hans, a native of Wisconsin, positions his step-ladder under the roof because he believes his gutters are clogged and desires to save them from ice-damage. So much is part of the intuitive self-understanding called folk psychology.
2. Scientific materialism.
The very idea of agency is problematic for scientific materialism. According to scientific materialism, everything that happens can be explained by the undirected behavior of matter. An event can occur as the result of a lawful regularity, or because of chance, or because of a combination of law and chance, but if matter is all there is and matter has no goals, then the appearance of goal-directed behavior is difficult for the scientific materialist to explain. Some materialists, like Paul and Patricia Churchland, think that agency is incompatible with materialism, and must be eliminated in favor of the materialistic categories of neurophysiology. This strategy is eliminative materialism. Other materialists, like Daniel Dennett, Fred Dretske, and Jerry Fodor, see agency as crucial to our self-understanding as rational beings, but hope to show that it can naturally arise from materialistic categories. This strategy is called naturalism of the mental.
3. Eliminative materialism.
According to the Churchlands, folk psychology, with its talk of goals and purposes, beliefs and desires, is simply the last vestige of a pre-scientific worldview already largely displaced by the advances of scientific materialism. The laws of physics make no mention of the "goals" of heavenly bodies. Darwin, it is claimed, removed the need to speak of an intelligent designer of living organisms. The last frontier to be conquered is the human mind.
For the Churchlands, there are no such things as beliefs and desires. Beliefs and desires have to go because they have intentionality: Unlike material entities, beliefs and desires include thoughts about something with propositional content, such as the belief that gasoline prices have risen or the desire that gas prices will fall. Thoughts can be true or false, they may lack a real object (e.g. beliefs about leprechauns) and they may jointly provide a reason for an action, such as buying a hybrid automobile. By contrast, material events either happen or do not happen (but cannot be true or false); they can only stand in causal relations with other material events (so they cannot point to non-existent objects), and though they may cause a behavior, they do not give an agent's reason for doing it.Continue Reading at