Functionalism and Materialism

In the article “On Functionalism and Materialism”, Paul Churchland elaborates on the materialist theories of mind. He explains three competing positions: reductive materialism, functionalism, and eliminative materialism, and adduces arguments for and against each of them.

Reductive materialism or the identity theory says that mental states and brain states are numerically identical. Examples of the established similar pairs of entities are light and radiation, sound and waves, heat and kinetic energy. Someday, identity theory claims, “folk” psychology will be reduced to neuroscience as a theory with higher predictive and explanatory force, and its corresponding set of principles. Churchland lists four main arguments for identity theory: (1) humans have physical origins, (2) all other animals originate exclusively in the physical world, (3) mental phenomena are neutrally dependent, and (4) success of neuroscience in explaining behavior of simpler creatures in terms of the structure of their growing nervous systems. The arguments against identity theory mainly capitalize on the Leibniz’s Law. They state that mental and brain states are different because they possess distinct spatial, observational, and knowable properties. All these arguments are refuted as either being fallacious or missing the point.

The second challenging theory, functionalism, states that each mental state is defined by its relation to its environmental effects on the body, other mental states and behavior.

Functionalism successfully incorporates examples that identity theory does not – creatures having different physiology but experiencing the same mental states. It allows studying systems and intelligence in terms of their functional, not physical organization. The criticisms of functionalism include inverted-qualia and missing-qualia arguments attacking the absence of physical qualia of mental states. These arguments are countered by admitting the reality of qualia and insisting that these qualia are not essential to mental states but varies across different subjects. The most problematic is the claim that psychology is irreducible to physical sciences. Using an example of ‘temperature’, Churchland shows that mental states are not necessarily irreducible; their reductions only have to be domain specific (326). Apparently, this shows that we may expect reductions of mental states to brain states and that psychology is not fully autonomous.

The third theory, eliminative materialism, claims that with the advancements in neuroscience, no match-ups for the mental states will be found, and the old “folk” psychology will have to be discarded as misleading. Churchland cites historical examples of concepts that were eliminated: caloric fluids, phlogiston, celestial sphere, and demonic possession. Eliminative materialism is supported by three main arguments: there are many explanatory and predictive failures in “folk” psychology; we never make correct theories from the first attempt, while “folk” psychology is such; there is much higher a priori probability that the true principles of how the brain works will not mirror mental states, and the latter will not be reducible. The weaker criticisms of this view capitalize on direct observation and wordplay and are easily refuted. The stronger one points that eliminative materialism is overly dramatic – “folk” psychology has been successful in many aspects and its complete elimination is unlikely.

References

Churchland, Paul M. Matter And Consciousness. Cambridge: MIT Press, 1984. Print.