Good post. I'm not sure that I'm a positivist myself and I think that the 'God is incoherent' can be justified on post-modern grounds. I'll give it go.

Given that we understand the meaning of 'reality', yes.
(This comment will probably become more important later on.)

My justification for logic is usually that it's a consequence of understanding the language properly. E.g. if you say that something is both x and not x then it would seem that you have no understood how to use the word 'not'. If you carry on using language like this, the word 'not' become worthless.

(Imagine telling someone you're not a theist and them then saying "but you could still be a theist" - it would be as if the word 'not' hadn't meant anything to them.)

Um... I think we have it the other way around.
Existence implies an ontology but an ontology doesn't imply existence. (e.g. I'd say that a unicorn has an ontology, i.e. if it existed it would be as an animal, but it doesn't really exist.
Then again, ontology is one of those words that I've never fully understood and have picked up by how I think people are using it!

I'd add to this the clause 'when talking in the context of objective reality'. We can talk in other contexts and 'language games' where 'ontology' is irrelevent.

This one I'm fine with.

So long as the 'positivist' recognises that their rules are limited to the context of empirical reality, this isn't a problem.

'only'?
(I'll build on this in the next paragraph! )

I agree with this. For me, this is a modern linguistic restatement of Kant's transcendental idealism. He believed that objective reality existed regardless of the human mind (contradicting Berkely) but was filtered through our way of thinking.

Right. But for communication to be possible then it is necessary that we have 'agreed' on a large part of it. So given that we are communicating, the rules are no longer arbitrary but transcendentally necessary.
"I think therefore I am" has become "we talk therefore we are sharing some constituted rules that we necessarily agree to."

Here we go back to my 'justification' for logic above, and my claim that once we are communicating, the rules of the language in use have become 'necessary'. Further more, 'reality' as we understand it is the 'reality' that is filtered to us through our understanding.
So as logic is based on the rules of language that constitute reality as we understand it, and as our communication implies that we share the same understanding, for all practical purposes, logic does accurately reflect 'objective reality'.

Yes, but where the foundations depend on social constructions, these constructions are also necessary for any discourse on the subject. So if we are discussing matters of science then we have already accepted these foundations.

I think this is a post-modernist misreading of Kuhn's work.
Kuhn pointed out that science couldn't be neatly summed up by a buzzword like 'induction' or 'falsification', but that didn't mean that the distinction wasn't justified. It just meant that the distinction was a 'simple' one, that there were a number of complex factors involved.

Ofcourse. However, the physicalist system of discourse is the one that has grown out of our competence in dealing with 'reality' (given that we understand that time in the everyday context) so when we talk about 'reality' and 'facts of the world', the materialist rules apply. When Gav challenged us and pointed out that language could be used in 'non-referencial contexts' we said "fair enough, but most theists use 'God' in the referential context of 'reality'. Our argument is against their theology. If you gave us a new theology involving a God that doesn't refer to something in 'reality' then this argument would no longer be effective."
However, he didn't give us another context for God.
It appeared that he wanted to make use of 'alternative contexts' to discredit our argument without following the consequences of an 'alternative context' to his theology.

That said, if a 'post modern vs positivist' debate kicks of in here, I'll likely take your side in a lot of issues. I think that the RRS argues effectively against fundies as they are talking in the same context as us - 'reality'. Most people agree that atheists like at the RRS don't understand moderatism at all, with the positivist assumption that any relevent religious claims will be those made about 'physical reality' and that anything else is 'woo woo'. It'll be an interesting topic.

I accept that sometimes our language use can be a bit looser, and it depends on our individual competence to interpret the meaning correctly within the context that it is being used. What 'logical language' does is recognise a particular part of our discourse, (our description of 'reality'), recognise the nature of this discourse and then devellop the rules to optimise it's function to its purpose.

Part of this purpose is to make it as clear, unambiguous and as easy to analyse as possible. It is ideal for settling disputes and obtaining the most accurate results possible from this kind of discourse. So the positivists certainly have this in their favour. When it comes to truth about the empirical world, they take what we all naturally aim to do in this discourse to it's optimisation.

I think that they only have problems when they assume that all forms of discourse ought to fit into the same structure.

Really? I guess we should define what we mean by reality.
Sometimes when we talk of reality we mean straight empirical facts like "that chair is green" or "that table is to the left of the chair". So when we're talking about that kind of reality (and I think it's our primary use of the word 'reality') then logical language is surely the right one for the job.

Although I also recognise variations.
For instance, it makes sense to ask someone if they 'really' believe in something, but beliefs might not be (and in my opinion aren't) in the discourse of empirical reality.

Hmmmm... I disagree with this - I think it involves a contradiction.
It talks about a 'things in themselves' that is separate from our linguistic projections, yet to talk about 'things in themselves' is to put them within our linguistic structure.
What I mean is, what we consider to be 'truth' and 'reality' is necessarily grounded within our linguistic structures. So our 'logical representation' isn't removed from what it 'represents' because our idea of what it represents is defined by the very linguistic structures that our logic is based on.

(I'm not sure if I'm wording this well. Are you following me here?)

My point is, the argument in the quote above implies a reality outside our linguistic structure but I maintain that's an incoherent notion. Our notion of reality is defined within our linguistic structure and to attempt to abstract is outside of that is to surely steal the concept?

Hmmm... I think a clash of discourse was involved, but I'm sure I remember both Hamby and myself wizening up to this and directly asking him that if his version of God didn't involve a referrent, what meaning did it have in what context?
We never got an answer from him, but that's possibly because he was waiting for the rest of the board to get there so he could tell it to everyone in one go. I think in particular he was waiting for Todangst.

I think a lot of the board suspected that he didn't actually have an alternate discourse for God, and was just trying to point out a technicality to make the argument look discredited, but maybe he had a genuine theology behind it. I guess time will tell.
A real clash of competing discourses regularly happens between me and a fellow called Topher. He's deeply entrenched in positivist thinking and we often spend several pages talking past each other in utter frustration!
I'll definately be linking him to this topic, and you'll see it nicely derailed as Toph and myself roll off on a giant tangent!

Sounds like I'm definately a post-modern thinker then!
The bit in bold in particular sums up my thinking.
Although I think that post-modernism's name has been dragged through mud by its reputation for being an excuse to avoid logical arguments, and to just agree to disagree rather than get to the bottom of things. But then maybe that's just the rhetoric I've been hearing from these darn positivists!

You're right in a way... I used the contradiction as the common 'no go' that the positivist assumes. It's not difficult to re-word my argument in a post-modernist wording. You've made the point that this context where we talk about 'things in themselves' need not have the literalistic use of 'not', but while you've told us what it's not, you've done nothing to tell us what it is.

Logical language tends to be the standard in philosophy, or atleast my assumed standard. So my noting of a contradiction shows that I was expecting your argument to be presented in standard philosophical language. If you are breaking from this standard then I can no longer relate to your wording. I now need you to explain to me what you are talking about. You seem to have ruled out most ways of speaking that I am familiar with and have difficulty seeing where the meaning of this 'style' of language lies.

Does this style of language relate to an 'everyday' style that didn't come to my mind, or is it a language that I can only understand within the context of a culture/practice/use?
The post-modernists might have a point that 'alternate' uses of language shouldn't be ruled out by default, but if they break from the norm then they need to explain themselves otherwise how can we be expected to understand a word they are saying?

Not clear on the antecedent for "it" in that last sentence.  What am I describing?  

 

The rules of argumentation, formal and informal logic and propositional calculus are all widespread, well-established conventions across not just philosophy, but also mathematics, semiotics, rhetoric and some branches of computer science.

While I haven't been able to backtrack the exact sources, the style of materialist metaphysics used on RRS is similar to that used by the "Analytic Philosophy" school which is a common orientation toward academic philosophy in English-Speaking countries (please correct me if this observation is wrong).  Continental European academics use a different metaphysics, as I understand it.  An informal poll of the philosophy professors around my campus (all U.S. natives) found very mixed feelings toward the metaphysics of Analytic Philosophy.  So it's a standard at certain universities and among the adherents of particular discourse communities, so this application of logic to questions of existence is not universal to the academic field of philosophy. 

In fact, this quote I came across by a guy named Clayton (should have written down the whole reference, my bad) seems typical of the kind of thing many academics in the humanities and social sciences are saying: "Due to postmodern considerations, claims of reason to universal validity and its claim to be able to derive important truths in a priori fashion from reason alone are now under severe challenge." 

Yep, this is a pretty good description of the overall view of postmodern thinkers toward language. 

What you're calling "standard philosophical language" is a formal system of meaning in which all the users have--to whatever extent this is possible--agreed on fixed meanings for particular terms and applied them according to consistent rules. This is only true of a few formal systems of meaning, and it's deliberate.

When breaking from this set of standardized conventions, it creates the situation where communicants have to explain what they are talking about.  In order to see where the meaning lies, the communicants have to establish a common set of (abritrary) discourse conventions and monitor the application of those conventions in realtime.

Why bother?  Because "standard philosophical language" is necessarily incomplete--like any formal system.  There are certain kinds of "meanings" that it can't get at, because representing them creates contradictions.  But when you change to a more flexible discourse, it allows for more types of meanings to be represented.

In this view of language, communication is not the application of a set of predefined rules, it is a negotiation.  Linguists like Austin claim this is how communication actually works: participants establish which rules of communication they share, then go back and forth between speech acts, hashing out additoinal rules as they go, and error-checking/correcting along the way until the desired goal is reached.  

In the first part of this response when I asked for the antecedent of "it," that's a trivial example of this kind of negotiation.  This discussion thread overall, though, is an example of a more multi-dimensional negotiation, with the object that we're each mapping terms onto other terms and concepts from other discourse communities.  Seems to me to be going well

Well I typically use an informal version of U.S. academic standard English when posting here, so it's not exactly 'everyday' language unless you spend every day at an unpretentious humanities academic conference (if there is such a thing).  There are various different highly-technical and jargony versions of postmodern discourse (the postcolonials are the worst, IMO), some of which require a lot of specialized knowledge to make any sense of. 

But I'm not talking about trading one formal system of meaning (standard philosophical language) for another formal system (academic standard English).  I'm talking about popping out of a single formal system into a kind of system of systems, to borrow terminology from Hofstadter.  This approach to communication looks at all the possible formal systems of meaning that could be used, picks the best ones, and applies them to the discourse in a self-conscious way. 

The argument for viewing language and discourse as a set of continous arbitrary negotiations is usually seen as starting with Derrida and continuing in Lacan (although there are important earlier influences as already mentioned).  The semoticians, especially Levi-Strauss and Saussure, added in components that made sense of the language relationships between (1) the thing being represented, (2) the thing doing the representation, (3) the person making the representation, (4) the audience, and (5) the rules that guide the construction of meaning out of all these diverse bits.  This was all done in the mid-20th century.  Since then, the basic view has been evolving rather than transforming, but the literature is extensive and exhaustive, so if you're interested I can point you to huge numbers of additional sources.

 

It's not my argument, Flaffer.  Luckily I don't have to defend it.

The much better, more complete, more exhaustive version can be found by reading several of the essays here. That's the argument you want to take issue with, not my incomplete summary of it.

It's not mine either. Thanks for presenting the link.

 

Yep, this argument is perfectly good, *within the realm of its own discourse.*   As has been proven repeatedly in many old threads I've read on RRS, it's airtight and cannot be shown to have any major problem as long as its basic premises are accepted.

My point is that, once you introduce ideas from other discourses, it's not so airtight anymore.  These ideas from other fields are legitimate scholarly claims that question, not only the assumption of the validity of logic (which is kind of old hat), but also the division of concepts into "coherent" and "incoherent" camps and the portrayal of language as something that can ever have a reproducable relationship to concepts or reality.

I guess my objection is that I feel that sometimes RSS presents the "'supernatural' or 'immaterial' are broken concepts" argument as a widely-accepted or monumentally unassailable scholarly consensus  (or irrefutable truth).  In fact, it is an argument that struggles with other equally valid claims in the arena of ideas.

Dare I say, "Typical response from a postmodernist."

Your parenthetical denigration of logic as a means of understanding is getting tiresome.

I am hoping that by re-reading your initial post you will see the hypocrisy of calling this argument as

You're not playing by your own standards.

 

I suppose my argument is that some people want these things to be real so badly that they will find any way they can to justify them even using fringe philosophy.

Also, this is not to say that the materialist position is 'irrefutable truth' and if I ever hear of a 'scholarly consensus' then I will be sure to let you know.

So no one lays claim to the argument I eviscerated earlier. I can see why, seeing as it is invalid and nonsensical. I would note that even summaries of arguments can fail because either they are bad summaries of an argument (they do not reflect the author's actual argument) or they build the argument in such a way that they are uncharitable to the author's intent. So I guess it is the former in this case.

Anyway, let's get to what todangst does argue:

I would respond that there are some explicit assumptions in this point. First, it is not the case that all forms of 'supernatural' and 'immaterial' refer; adjectives do not refer to anything. So, todangst must want to say that the noun forms of the terms are the ones that are "attempts at reference".

But this brings me to my second point: not all expressions refer and, I would claim, terms like 'supernatural' and 'immaterial' are not of the class of referring terms. They are more like abstract concepts like 'cancer' and 'art'. These expressions do not refer to any physical object.

Marga Reimer puts the point this way in the Stanford Encyclopedia of Philosophy's entry on reference:

It seems to me that the terms todangst is using are more like terms like 'art' and 'cancer' then 'unicorn' or 'chimera' (in its noun form).

Actually it's possibility c), which is that there are many different forms of discourse that deal differently with "incoherence" and "things in themselves" and I didn't choose a particular one to describe. Probably the two that I'd be most familiar with are semiotics and speech-act theory, if you'd like me to present either of those in another post.

 

My info from history history suggests this is factually incorrect. The earliest known attempts in the West to codify the language of logic and argumentation come from the Classical Greeks, especially Aristotle, who made it their stated objective to lay down the rules by which claims could be analyzed systematically. Since then, these rules have been expanded by scholars (not ordinary people) and taught as an academic subject. What I'd call 'everyday language' has many features in common, but doesn't consistently apply the rules used by the formal system called 'logic.'

Well I've seen the claim "supernatural things exist" presented pretty frequently on RRS, and it always seems to get the response "supernatural is incoherent." That suggests to me, unless I'm misunderstanding something, that the form of logical discourse that concludes "supernatural is incoherent" is incapable of representing information about terms like "supernatural."

The subject is vast; people spend their whole professional lives reading and writing about it, and there's no substitute for reading the primary sources. But Christopher Butler's "Postmodernism" is a good, short and accurate introduction

Yep, it was a summary, and in this case it was a bad summary resulting from a still-incomplete understanding of the original argument.  I don't need to uncharitably misrepresent someone else's argument in order to eviscerate engage in productive discussion about it.

And good luck with your argument against Todangst's argument.  A brief glance back through the threads in this forum will reveal that you're the fifty jillionth poster to make these exact same counterarguments.   I doubt you'll have any more success in arguing against Todangst *within the terms of materialist metaphysics* than any of them did.

I was just reacting to the particular post by textom. If no one actually makes the claims in it, then so be it.

That is exactly what i mean: ontological status does not imply existence; if possibilism is true, there are entities that do not exist (i.e., are actual) but do have ontological status.

I do understand how the term 'nothing' , as part of the term's definition, is related to the term 'something' (i.e., "nothing" is the denial that there is something, among other things). However, I am not sure how you think this is related to the notion of "coherence". Do you mean something like "understandable" or "makes sense" and "incoherent" would mean "nonsense" or "not understandable"?

Here's a brief version of Semiotics, then.  I'm going to have to simplify and leave a lot out, but I'll be happy to elaborate.

C.S. Pierce was the first to see the "sign"--the basic unit of meaning--as a relationship between three elements: the 'real-world' object being represented, the symbol that represents it, and the audience that makes meaning out of the other two.  Pierce's great innovation was the idea that the relationship between these three elements can't be reduced to a relationship between any two of them--all three must be considered in the construction of meaning.

So already the Classical idea of a correspondence between symbols and the things they represent was called into question by this early version of the "semiotic triangle" that introduces a third element that is necessary for meaning.  It's notable that pierce himself was a dedicated logician, but he saw logic as a sub-branch of semiotics, a branch specialized for making particular kinds of meanings.

Since Pierce there's a huge list of semioticians who made big contributions, but basically they've all made additions to the original semiotic triangle, pointing out that in order to have meaning, you not only have to have a signifier and a signified and an audience, but also a code for interpreting the relationship between the signifier and signified, an audience that is aware that it's participating in a meaning-making activity, context of occasion, culture, previous interactions between the participants, intentionality of the sign-maker and various other interesting hobbyhorses.  Some semioticians make a distinction between a "signified" as an internal linguistic entity, and a" referent" as an external phenomenon in reality, but not everyone bothers.  If you go to Google images and type in "semiotic triangle," you'll get a sampling of the models that are out there in the arena of ideas.

 So unlike logic, which deals with a limited subset of the possibilities of language and (in some schools) seeks to define and categorize consistent relationships between language and thought (or language and experiences), semiotics both (1) incorporates the language of logic and (2) moves beyond the subset of language studied by logic to encompass all possible ways of making meaning.

I'll illustrate with a concrete example, borrowing heavily from J.L. Austin's speech act theory. The other day I told my wife, "I put the hairbrush on the desk," by which she understood "I put the toothpaste on the sink."  This is a true story.  I couldn't think of the words "toothpaste" and "sink" at that moment, so I used whatever words I could come up with instead.  Because of what we'd been talking about earlier that day and because she's used to my linguistic eccentricities, she understood what I meant in spite of what I said.

There is no set of consistent rules that guides the substitution of the words "hairbrush" and "desk" for the words "toothpaste" and "sink."  The decoding of the meaning of the statement was entirely context dependent, and derived not from any kind of predictable or reproducable conventions of language but rather from my intention as the speaker, her contextual knowledge as auditor, our personal code of communication that we use between us, and the experience of all the communications we've had in the past.  According to Austin, this type of communication--along with an extensive vocabulary of grunts and gestures--is what makes up the majority of communicative acts.  Pay attention someday and you'll notice how few words people who know each other actually use.

So from a semiotic perspective, declaring something "incoherent" doesn't end the conversation.  When you say something is "incoherent," all you've done is describe it as having a particular characteristic terms of logic, which is itself only one method within the larger realm of making meaning.  It would be more accurate, in semiological terms, to say something like "'supernatural' is incoherent in logical terms," and then move on to talk about other ways that the signifier 'supernatural' means things.

Yeah, I had to skip a lot and Peirce isn't really widely used.  I could easily have started with Saussure instead.  Peirce's triangle is more simple than most: a much more common one these days is the one that designates the signifier, the signified, the audience, and some aspect of the context or code used in communication, either as another point in a semiotic "pyramid" or variously along the lines that connect the points in the triangle.

As I mentioned briefly (but it didn't stand out) many semioticians bypass the problem of referents by insisting that the 'signified' is separate from the 'referent,' with the referent being the actual real-world phenomenon, and the 'signified' being the mental image of the referent that is created in the audience (triggered by the signifier). So under this way of doing things, it doesn't matter if referents are verifyably 'real' in any sense, because we're only dealing with mental states when we talk about meaning.

Personally I'm of the camp who prefer to say that it doesn't matter for the purposes of semiotics whether or not there are really real referents or not. We only have access to systems of representation organized with language.

I more or less agreed with everything in your semiotics article, but I think that it's a case of misapplication to bring it up in the atheist vs theist context.

Very well, but the meaning that we are discussing in the context of 'is there a God' is usually within a logical discourse. E.g. there's a rhetorical effect to a real person wanting you to do something compared to a fictional monster.
Theists often want to make use of reality rhetoric, but when questioned will try and fall back on a different discourse. Trying to have their cake and eat it, so to speak.

 

The reason why this is usually missed out is because it is implicitly clear that both parties are aiming to talk on 'logical terms'. Although the theist might be referring to other forms of discourse, this is an unintentional conflation and we need to be able to point this out in a clear way.

Yeah, Josh, we all know our Godel, hopefully.  It's implicit in any discussion that uses the deconstructionist premise that "meaning is arbitrary" that we have to accept the premise and then go ahead and discuss it using (abritrary) language constructions. 

Maybe it's all wrong.  Maybe not.  I choose to accept the hypocracy and talk about it anyway because, hey, it's a good living.

But whether or not this is the case is moot; unless you can provide another means for rendering these terms meaningful other than through reference, holding that there are other ways to render a term meaningful in of itself does not provide meaning for these terms. Please recall that the problem is actualy twofold: terms like 'supernatural' are universal eliminators, they rule out any universe of discourse. They can only be used as contradistinctives of 'anything' and thus are synonyms for 'nothing."

A point discovered not by me, but by theologians and buddhists alike. 

Such expressions do not rule out any universe of discourse.

I disagree. However, we need not focus our battle here, as the second dilemma concerning the universal eliminative 'nature' of these terms remains as a problem.

Abstract concepts make references. But the real point here has to do with identity itself.  How else can you make sense of a term like 'cancer' or 'art' unless you instantiate mentally it in some manner? How can you think of something without any identity?

I don't see how this is possible, unless by 'physical object' you mean 'an actual object before me." Yes, they can exist as abstractions alone, without an extra mental existence, but how can a concept exist unless it is instantiated as a mind object?

We can talk about a 'cancer' of the soul, but to 'know' that there is such a 'cancer' we point to objects, either real or imagined, a behavior, an action. Otherwise, what meaning can the term have, denuded of any identity?

At any rate, you may disagree with this all you like as it is not significant to my point: the key point remains that even if you reject these terms as attempted references, you must still explain 1) what they can mean, in the face of the reality that they eliminate any universe of discourse.

Again, this is moot (as I say in my original essay) unless you can utilize another way of providing meaning for terms like 'supernatural'. Again, the second problem still glares: these terms rule out any universe of discourse.

 

Then please read the above post.  Again, I do no see why discussions of 'abstractions without real world correlates' and 'real world entities' even arises in this discussion, as the discussion relates to a priori matters: the axiom of identity. No real world correlate need apply.

 

I mean it in the most basic, metaphysical sense of the axiom of identity.To define an 'entity' in such a way as to violate the axiom of identity is to render the term meaningless, unless and only unless the term is intended as a contradistinctive.

 

Correction: items (2) and (3) in my illustration of cultural semiotics above should refer to "signifier" rather than "sign."  A slip of the typing, and the forum won't let me edit the original post.

Actually for the sake of completeness, this isn't entirely accurate.  There are two ways (there might be one I'm missing) to attack the "'supernatural' is incoherent" argument within it's own rules, both of which consist of making counterclaims to basic assumptions:

1. The "Doesn't everyone need..." essay states that grounds for naturalistic assumptions are sufficient to justify those assumptions.  It could be argued that the grounds are not sufficient.

2. The "Problem of Induction" essay argues "If you don't look for certainty, and you know about modern probability and statistics, the problem of induction is not a problem at all."  It could be argued that the questions at stake here (e.g. existence) require that certainty be taken into account, and therefore the problem of induction is a problem.

But both of these counterclaims are, like the original claims, assumptions.  So any dispute over the validity of the claims would boil down to a matter of opinion.

Yes, I also see the resemblance, and I'm glad there's some common ground  

I wouldn't go so far as to say that all people are familiar with this linguistic practice.  I'd agree that everyone has access to the rules of the practice, and people can pick up the important parts pretty quickly, but only a tiny minority of the people really have a grasp of it. 

 

Yes, I see this assumption at work, and I agree that it is often justified and I don't have a problem with that.

My issue is with these other assumptions, that I also sometimes see at work:

(1) The only allowable definition for words like 'God' are the materialist/natural definitions; the only permitted references to concepts like 'God' are the ones that use this definition.

(2) Any discourse that departs from the conventions of materialist metaphysics is defined as meaningless and therefore can be discounted (the positivist position).

(3) (putting this one up even though I'm not sure about it) The formal system of logical discourse (as defined by concepts selected from the tradition of Analytic Philosophy) encompasses all possible valid reasoning.  Any mental activity which departs from this formal system is, by definition, not descriptive of any question pertaining to metaphysics.

(4) all the starting assumptions of the "'supernatural' is incoherent" argument are true. 

Typically the pattern I see is the theist using 'God' is defeated by the materialist argument, then tries to change to a different discourse (or explore other discourses) in which the still-existing issues can be discussed, but can't get anyone to come along on a search for common ground.  The materialist side of the argument refuses to recognize the shift in discourse (or discounts all other discourses as meaningless) and continues to insist on the original assumption about the use of terms like 'God.'

And now I'm back around to my original rhetorical point: if RRS's goal is to win formal logical arguments, then you have succeeded.  If your goal is to map out a strong, consistent materialist argument against the existence of God, then I don't know of any better argument--well done. 

If your goal is to persuade an audience to come around to your viewpoint, maybe not so much.

Cool, I'm happy with this outcome. I like RRS, and I'm interested in seeing it do well in the arena of ideas. If my professional opinon on how the case against the more mindless forms of theist dogma can get an airing and some fair consideration, that's all I ask.

I agree that it's not necessary to always qualify everything with "under the assumptions of X"--it's cumbersome and more effective if made clear from the outset anyway.

I think the naturalist assumptions are very persuasive. I find the extra step in those assumptions (that I'm characterizing as positivist) that the justification for materialism excludes the possibility of anything else is less persuasive, but that's a topic for another thread.

And finally, based on my own pre-de-conversion experience, I believe that the assumption that many theists consciously or unconsciously already use is that God is an entity who is not material, but who has an effect on the material universe.

(And just a little N.B. reminder here for anyone reading this who is tempted at this point to try to argue with me against this characterization of God: it's not my characterization; it's my interpretation of a common theist characterization.)

And this is where the communication invariably breaks down. Even when shown that the concept of a 'non-material entity' is incoherent in logical terms, the jump to "therefore cannot exist" or "therefore cannot be talked about" is the part that is not persuasive in most cases. Logical, valid, but not persuasive. There's always an escape hatch through special pleading for the nature of God (which is not *fallacious* special pleading, in the theist mind, because it is justified by assumptions about God's unique role in/relationship to the universe).

IMO it is necessary to to temporarily take on a system of meaning that is capable of engaging these incoherent ideas in order to continue to engage the audience in productive dialog at this point. It doesn't weaken the materialist argument or invalidate its conclusions to temporarily suspend its verdict or admit its possible flaws.

Hope this is actually helpful and not just me riding my iconoclastic hobbyhorse.

I haven't forgotten about the Davidson: it's still in my queue.  I looked at it, but saw that I'd have to spend some time working through it before being able to develop a response.  I'll work on that next.