### Reason and the First Person -- The Golden Presumption

[Note: the contents page for this series can be found here. This is the first entry of Section Two, but the prior chapter (13) is a summary of positions developed throughout Section One.]

In geometry, as every high-school student is taught, all theorems and other geometric rules can be deduced from axioms. The axioms you use, determine the type of geometry you have. In Euclidian geometry (the kind normally taught in high-school), there are three axiomatic assumptions which cannot be proven, and upon which everything else depends. Points have no dimensions; lines consist of an infinite number of points in one dimension; and planes consist of an infinite number of lines in two dimensions. Solid-body or 3-D geometry extends the classically Euclidian axiom set to include a volumetric space with an infinite number of planes in three dimensions.

No one can prove any of this, but not to assume these axioms can lead to nonsense. (Curiously, the chief axiom--that points must be presumed to exist yet also to have precisely zero physical characteristics--might itself be considered nonsense in light of a naturalistic philosophy.) Nonsense does not necessarily follow by changing these axioms; that is how non-Euclidian geometries were developed. But the more basic and fundamentally necessary the assumption, the more likely that any alternate assumption will lead to nonsense.

The most basic and fundamentally necessary assumption should therefore be one that would be nonsense to deny. Such a key assumption (or presumption) will be the bedrock from which trustworthy deductions may be drawn about the rest of reality--it will be a reliable foundation, because to deny it leads precisely nowhere.

[See first comment below for extended footnote here.]

You should be able to understand immediately why theistic presuppositionalists want to put God in this spot. The language I must use to describe this 'Golden Presumption', is language that most properly applies to God--if He exists.

But I should be careful here. I am only talking about an assumption that is a tool for my purpose ('To deduce characteristics of ultimate reality'); and I think even the presuppositionalists would deny that God should be considered a tool for my purposes! What seems to be the proper position due His dignity, becomes a position beneath His dignity (if He exists) once we put the position into practice. God is not a tool of metaphysics. I will not be using Him as such.

There are other problems with putting God into the Golden Presumption slot. As I argued briefly in the first Section (during my chapter on presuppositionalism), it doesn't help the sceptic. A hypothesis of God's existence for purposes of argument, is not necessarily a bad thing; but it becomes mockery when the purpose of the exercise is to argue that a person (especially an atheist or agnostic) should accept God's existence! A theist would not (or at least should not) stand for the same thing if the shoe was on the other foot: I see no good reason why a religious presuppositionalist, or anyone else, should accept that God does not exist based on an argument which proceeds by requiring God not to exist.

(I suspect a large number of sceptics are sceptics precisely because, having been taught by certain theists that arguments are supposed to be built this way, they subsequently discovered this misapplied argument could be developed just as easily from the other direction. This misapplication does have some similarity to a properly abductive argument--but a properly abductive argument is not trying to deductively prove its hypothesis, which is how the problem of malignant circularity arises.)

There is at least one more problem with putting God into the Golden Presumption slot: He never quite makes it there. Even presuppositionalists tacitly assume one more key position, prior to their construction of an argument based on God's required existence: they presume that they (and their audience) can think.

They may deny they are presuming this before presuming God's existence, of course; and I grant that they deny it out of reverence and prudence. They don't want to claim they are putting themselves before God, and I think this is an entirely proper attitude. Nevertheless, they are humans, not God themselves (most Western theists would agree with me at least on that). They have to start from where they are.

Let me put it another way. I do not perceive that I am God. I am, or at least perceive I am, a human being (leaving room to discover maybe I’m wrong about this and am actually God after all. I’ll be covering this much later in Section Three.) I want to discover whether God exists, and I want to help other people discover whether He exists. I will build an argument to help them and/or me. (This argument could even be as 'fundamentalistic' as "The Jewish and Christian Scriptures are all God's direct verbal revelation to us.") But in doing so, I am flatly presuming that I (and you) can think.

It doesn't matter whether my goal is to argue against God, or to argue to God, or to simply argue about God (in order to discover whichever way the argument may lead). It doesn't even matter whether I am using metaphysical argument or basing it 'purely on Scripture'. I am arguing; that means I am working from a necessary presumption (even if it is an unstated one). The presumption is that I, and you (my reader), can think.

(I am not yet considering any particular details as to what this presumption must entail. I'll get to that later.)

Already, then, I have an interesting candidate for the Golden Presumption: your and my own sentience. It is a presumption a sceptic and believer may both accept (regardless of relative belief and scepticism on whatever topic). It is a presumption that underlies every argument we make, and can be easily seen to underlie every argument--if we bother to look for it. A religious presuppositionalist will have to work very hard to convince a sceptic (or anyone else) that the sceptic actually presumes God's existence (as such) every time the sceptic begins constructing any argument! But that is the type of characteristic necessary for the Golden Presumption: it should be a presumption that underlies every possible argument, whoever develops the argument.

What happens if I deny this proposed presumption--that you and I can think?

I am not sure it is even possible to do so. Technically, it is possible for me to utter the sounds (or my fingers to peck out the words) which correspond in English to "I cannot think"; but for those sounds to correspond in reality to the general meaning they hold for someone who understands the English language, would entail (it is a tautology) that I cannot in fact think. This would mean that I (as myself) would quite literally have 'no reason' for saying the words even as a groundless presumption: no understanding of what they imply as 'language', no consciousness of their meaning as such. (My largest chapter in Section One, "Belief and Reason", features much more discussion on this topic.)

That being the case, how could I be 'denying' or 'asserting' anything by this event? It would not be 'me' 'doing' it--my body would be reacting in some fashion to environmental conditions of some sort to produce the effect, or perhaps some other real sentience would be using my body as a puppet.

(This latter position wouldn’t necessarily deny the presumption in an absolute sense; the “I” would be some other thinker pretending to be me. This is why fictional characters and entities can still be treated as making arguments--behind their (fictional!) efforts is a real thinker somewhere.)

For 'me' (myself) to 'deny' that I can think, requires that 'I' have 'some idea' of what 'a denial that I can think' 'means' and then 'actively' deny it: in short, such a denial by me (as 'myself') requires that I can actually think! This would be necessary, even if I never bothered to take the position any further than the asserted denial "I cannot think."

I am loath even to speculate for the sake of argument that such a proposition ("I cannot think") could be granted. Setting up, as a (much more the) chief presumption, a proposition which in fact we don't believe (and notice that you and I would be both denying this speculative proposition merely by 'speculating' about it!), runs the terrible risk of accepting a nonsensical position as viable from the outset--leading to folly which must grow more profound (and more subtle and subsequently harder to detect as such) as positions are developed further and further ('for sake of argument') from it.

However, in case you, the reader, have missed my point here (or perhaps you think I have made a mistake), I can make the same point by ignoring the question of whether such a position ("I cannot think") makes any kind of sense to propose.

So let me simply brutely propose it, and ignore the issues surrounding the cogency of the event of the proposal: I cannot think. Very well. What happens if I attempt to deduce (or otherwise infer) further positions from this proposition?

Next up: either a really really short entry (because I cannot think!), or further inquiry into an alternate Golden Presumption...

Jason Pratt said…
[Extended Footnote]

Time to clarify how I will be, and have been, using 'deduction' and 'induction', as well as ‘abduction’!

An inductive argument would look like this: these are taxis; all these taxis are yellow; therefore we may reasonably expect further taxis (and maybe even all further taxis) to be yellow.

An abductive argument is a special form of induction, and would look like this: hypothesizing that all taxis are yellow, how well does the data fit this hypothesis? The extent to which the data fits, counts as weight in favor of us reasonably expecting all taxis to be yellow.

A deductive argument would look like this: all taxis are (presumed or previously established to be) yellow; this is (presumed or previously established to be) a taxi; therefore, if these propositions are true, this taxi must be yellow.

Not all of my 'deductive' arguments will have precisely this form; but the underlying principle will be the same: I will be examining the implicative constraints either of necessary presumptions (which requires establishing them as being necessary, of course), or of previously established conclusions based on a running chain of such inferences, in order to discover what the constraints must necessarily entail.

A constraint (as the word implies) prevents some option(s) from being true; discovering the implications of a constraint therefore involves either tacitly or explicitly removing (or 'deducting') one or more options that might otherwise be proposed as following from a necessary presumption or a previously established (deductive) conclusion (now being used as an assumption for new inferences).

When the options that could be proposed also can be grouped into two mutually exclusive classes; and when the constraint necessarily removes one option group without necessarily removing the other; (and if the assumptions have been properly established) then the remaining option (or option group) should be considered to be true.