A distinction of 'as if' circumstances

Here is a case:

TPO: "We can talk about the world as though it contains physical objects."

TPO is clearly true - we do talk about the world this way.  But we want to say something a little bit more:  that this talk is true, or correct.  We say that for this to be true, the world must contain physical objects.  And, of course, the problem with that is to say "The world must contain physical objects" is no more than to talk as though it does.

Suppose we construct some metaphysical or naturalistic theory to get around this - let us say that either (a) the fundamental structure of the words includes physical objects or (b) our talk is somehow the consequence of the existence of physical objects.  All theories of this type will either (i) be further "as if" talk already incorporating and referring to physical objects, or (ii) "as if" talk incorporating and referring to processes and structures which are equally difficult to render epistemologically explanatory.

The only way forward, then, is to forget the "physical objects" bit and focus on the "talk".  The fact that we can talk is not a different kind of fact from the fact that there are physical objects in the world, except that we can't question it.  To question it, we need to be able to talk.

We cannot, either, be 'silently skeptical' in any intelligible way - it is impossible to construct grounds for attributing such a skepticism to anyone, or for denying it of them.  It has only a formal possibility - and it is a possibility which is consistent with any facts or denials of facts whatsoever.  It is a possibility which has no consequences - it neither allows anything nor excludes anything.  It is, from certain perspectives, difficult to know what a statement of such a possibility could mean.

Let's compare TPO with TSP:

TSP: "We can talk as though star signs predicted personality traits."  This is the scary possbility that epsitemological realists want to deal with.

Clearly, some people do talk as though star signs predicted personality traits - they say things like "Star signs predict personality traits".  Why doesn't this count as the same kind of 'as if ' as the one we find in TPO?

The answer here is not to do with any metaphysical or naturalistic circumstance.  It is because we can only rescue "Star signs predict personality traits" by radically adjusting the meaning of 'predict'.  It is very clear that object language talk produces predictions in a very different sense from the sense used by astrologists.  Or, if 'predict' must be held stable, then 'personality traits' will have to go - we have to accept very different ways of attributing these from the ways adopted by psychologists, or even by reasonably astute lay observers.  We cannot work out the rules governing this conversation well enough to know how to continue it beyond repetition of the core liturgy.

Can we make 'physical object' talk fall apart in a similar way?  No.  There are clearly contexts (e.g. metaphysics ...) where this talk becomes very peculiar, but this is an extreme test.  There are no contexts in which astrological predictions of personality traits can be incorporated reliably into a productive and meaningful conversation.  We might play with the words in instrumental or aethetic contexts, but we cannot play the language game of scientific theory.  They do not bound a conversation in a creative, sense-making way.  If we insist on taking their truth 'literaly', their meanings, and so even the possiblity of 'literality', disappear.