Any discussion of materialism should cover the mind-body problem so I will began with this point then offer two differing approaches to materialism which I tongue-in-cheek call Platonic Materialism and Aristotelian Materialism.
The mind-body problem developed during the scientific revolution which built firm conceptional walls between the objective and the subjective. Science must provide a mathematical precise description of external reality which was universal and therefore true for everybody everywhere. The subjective individual perception of the universe was stripped from this account and regulated to the human mind as effects produced by external matter. The discovery of evolution through natural selection and the rise of molecular biology further strengthened the case for materialism. It was assumed science would continue to advance and eventually offer an unified account of reality which encompassed the human mind within physical laws. This attempt to unify the objective with the subjective, physical laws governing matter with human freedom, biological evolution with human ethics, mathematical accounts of matter with art and beauty, all lies at the philosophical heart of materialism.
I now offer two different approaches to materialism.
The first I call Platonic Materialism (yes, yes I know). Plato, the leftmost figure depicted gesturing upwards in the above extract from the School of Athens painting, believed knowledge is always proportionate to the realm from which it is gained [source] . We must ignore the ever changing world revealed by our senses in favour of universal transcendental forms revealed through reason. A platonic materialist will similarly offer a universal account starting with the big bang and working 'downwards' to encompass the subjective human mind: all things are made of matter created during the Big Bang. Eventually life capable of reproduction emerged from dead matter and developed through evolution to greater complexity including consciousness. Although not yet possible, everything can, in principle, be described by physical laws. Free will and our sense of self hood is an illusion and neuroscience has solved the mind-body problem.The Platonic Materialist can with justification be accused of scientism.
The second label is Aristotelian Materialism. Aristotle, shown on the right gesturing toward the ground, believed universal knowledge was found through studying concrete entities existing in space and time. An Aristotelian Materialist believes there some things which science cannot explain and therefore disagrees with the Platonic Materialist that physical laws can in principle provide a unified 'theory of everything' but does not accept this lack of knowledge as grounds for rejecting materialism. An Aristotelian Materialist is content to accept a disjointed worldview containing practical knowledge drawn from the sciences combined with the humanities and naturalistic psychology. He/She accepts ethics as subjective and is secretively pleased the mind-body problem still exists.
I admit the analogy is rather strained (it sounded much better in my head), but I do think it's worth distinguishing between a materialist searching for an unified account of existence through science and a materialist content to accept the limitations in human knowledge. Attacks on materialism usually concentrate on the former but the latter can be accused of having an incomplete and inconsistent worldview.
Posted by Gavin Doyle