The post-modern response to materialist metaphysics
Todangst asked me about this awhile back, but I had to go review my sources to make sure I was getting the credits right. So much of this is internalized into the discourse community of rhetoricians that it's hard to remember where some of it comes from.
Okay, as I understand it, the physicalist or materialist metaphysical argument against the existence of God, as represented on this site in general, goes something like this. Please correct me if I'm misrepresenting something:
1. An objective reality exists; humans access this reality through perception
2. Personal existence and identity are axiomatic because any attempt to refute them results in a contradiction
3. The laws of logic are axiomatic (this is an assumption, but is based on justification)
4a. Ontological status implies existence; the term "non-existence" has no ontological status
4b. In order to be coherent, a concept must have a positive ontological status
4c. Terms like "supernatural" and "God" have no positive ontological status, are therefore incoherent (and therefore non-existent?); these terms cannot be defined without committing a stolen concept fallacy
Postmodern thinking would characterize this system as "positivist," that is a system of meaning that deals with inconsistencies and contradictions by declaring them "incoherent" or "meaningless" and disregarding them. Postmodernists regard positivist systems as being cool in that they deal comprehensively with the problem of contradictions, but criticize the inability of positivist systems to deal with particular kinds of questions because the system acknowledges no meaningful terms to represent the concepts involved.
Personally I think the goal of eliminating contradiction from discourse is laudable, but any closed system of meaning is always going to come up against the limitations of its incompleteness. Why make those limits any tighter than they need to be?
It's hard to characterize postmodernism (a term I'm using here to also refer also to deconstruction, structuralism, post-structuralism, semiology and probably a couple of other things) as having a central argument, but the various parts share some commonalities. One main feature is the departure from the ontological premises of early 20th century metaphysics in favor of a language or discourse-based approach:
1. It doesn't really matter whether or not a material reality exists; humans only have access to our interpretation of it
2. That interpretation (experience, thought and knowledge) happen in language. Some theorists (Austin) allow that certain mental contents are nonlinguistic or prelinguistic, but others maintain that there can be no thought without language.
3. Language is socially constructed and arbitrary; there is no necessary relationship between a sign and what it represents. So reality is constituted socially in language. (Much of early post-modern thought is about how particular constructions of language and constructions of reality are politically motivated, rather than guided by empiricism.)
4a. Logic is a type of linguistic discourse, therefore its rules are socially constructed. We assume its validity, but there is no unquestioned assumption that the rules of logic consistently reflect the dynamics of an external reality.
4b. Science and empiricism are types of linguistic discourse, therefore socially constructed and their validity cannot be assumed without question. Some theorists (Kuhn for example) even go so far as to say that scientific discourse is not sufficiently different from other types of social discourse to justify a distinction.
4c. Because reference to an external reality is not necessary, questions of coherence, meaning and related physicalist issues are not, as it were, material. Every term and concept has meaning with reference to its own system of signs and its own community of discourse.
Deconstruction specifically criticizes traditional early 20th century philosophy for constructing all kinds of dualities--existence/nonexistence, valid/invalid, positive/negative--pointing out that these are just arbitrary verbal constructs that don't necessarily reflect the way experience works and really just function to privilege one type of experience over another (usually for political reasons).
In regards to some of the recent discussions on RRS about contradictions and incoherences, semiology would view these representations as perfectly legitimate. Rather than being meaningless or discardable, a contradiction is a sign that functions as a placeholder for a concept that can't be represented in dualistic logic. In this way, discourse is capable of dealing with any type of question and isn't restricted only to questions which are coherent within a particular construction of dualities.
Incidentally, postmodern discourse enjoys the same kind of invulnerability to criticism that positivism does. The only criticism you can make of postmodernism is made in (socially constructed) language, so it's contradictory in the positivist sense.
"After Jesus was born, the Old Testament basically became a way for Bible publishers to keep their word count up." -Stephen Colbert