The Primacy of the 1st and 2nd Person Perspective, the Roots of Validation

Hume's observation that we cannot demonstrate the reliability of our sensory inputs, but must, nevertheless, build our knowledge of the world from them stands at the focus of the modern analytic tradition in epistemology. How this observation is made and interpreted, how it 'works' within a community of language users, has had some attention. It deserves much more: We can only share Hume's skepticism if we have a shared understanding of what it is that he is skeptical about.

Almost the whole of philosophy (and empirical science) has oriented itself towards validating third-person narratives - validating that something 'is the case' as though this could be demonstrated independently of whether the statement of that something (or its contrary) is intelligible within our conversation (literally, the conversation between you and me). That this is an error is what we should have learned from Moore's paradox. It is the deep truth that Barry Stroud passed by when he dismissed the epistemological relevance of 'privileged statements'.

There is no such thing as pure third-person validation. A third-person conversation can only count as a conversation if you and I can agree on this. Our agreement about Hume - our confidence in our shared capacity to consider him - is epistemologically prior to anything he might have said.

It is, of course, difficult to imagine how our present conversation might remain intelligible to us if we disagreed very profoundly about certain historical facts, but that does not make the facts the grounds for the intelligibility - it makes our experiments with intelligibility the grounds for what we count (at the limit what we must count) as facts.

However counter-intuitive this might seem, it is - to paraphrase Sherlock Holmes - the only hypothesis which must survive a considered skeptical assault. While we might share doubts about Hume, we cannot intelligibly share doubts about our doubts about Hume without wondering whether we are, in fact, having an intelligible conversation about doubt. Or perhaps about anything.

Metaphysics studies what must be true for our conversations to be intelligible, without considering that intelligibility must be a test of metaphysics, and not vice versa. And intelligibility is not a 'third-person' attribute. We can always articulate a radical skepticism about the intelligibility of a conversation between third parties, but we cannot intelligibly articulate a similar skepticism about the conversation you and I are presently having.

More on Metaphysics ...

A way of talking that we are comfortable with can feel like it has metaphysical roots. Each member of a language community might (silently) refer to 'different' metaphysical roots of this kind, but still be able to sustain conversations with each other (this is an extension of the 'box-beetle' parable).

When we describe these roots, of course, we may find that we disagree. A characteristic of these descriptions (when nothing more nefarious is at stake) is that however different the metaphysical inspirations are, they cannot be distinguished on the basis of 'truth-conditions'. If they could, then some would not survive. Or the community would fragment - members would become unintelligible to one another. Truth conditions, after all, must also be intelligible.

Machines ...

 A machine is not just an object - or even a set of 'processes' (as in a computer program). For it to be a machine it must, in addition to this, be accompanied by a promise. For human-made machines the promise is from the constructor: 'I promise this will fulfil its function'. For 'natural' machines the promise is from the theoriser - the person articulating the hypothesis that the object is a machine - and it is a promise that this person knows how the machine works; knows what its 'function' is.

The 'stability' of machines is therefore a projection of our belief in semantic stability. We can only make promises if we know what we are saying, and we can only know what we are saying if, to some minimal extent, words mean the 'same' from one occasion of use to another.

This is one of the reasons why the 'fact' that we can construct machines and the fact that we can talk about the world are really the same fact.

Most machines are, of course, a bit 'unreliable'. Their accompanying promises are not always fulfilled. We can only make adjudications about this in a working language. (Collapsing bridges - which appear in many 'reality' diatribes - can only be identified through this kind of adjudication.)

What this means is that semantic stability underpins the identification and appraisal of 'machines'. Which, in turn, means that no 'mechanistic' account can be given of semantic stability.

(We should know this, of course, from the Goodman/Kripke paradox.)

We certainly can't intelligibly articulate a speculation that semantic stability is some kind of 'illusion' either ... nor even the related speculation that we might wonder about this privately.

So much, by the way, for mechanistic determinism. Which seems like a fairly trivial corollary, under the circumstances ...