I accept that my interlocutor was genuinely puzzled about consciousness. However I disagree with him both that he is puzzled about the nature of something and that what could relieve him of his puzzlement is a substantive theory which explains what that something is. That is, I don't believe his puzzlement is - despite the reflective self-understanding he with all integrity carries with him - akin to 'we don't know what meteorites are made of' (as uttered by, say, an 18th century scientist). I believe that, to the extent that his puzzlement really is best articulated in terms of a want of knowledge, what in truth he is wanting is knowledge of how to handle 'what is Y?' questions when the concept of Y is constructed by the substantialisation of an adjective (i.e. when you put 'ness' on the end of a word like 'sad', 'egregious' or 'conscious').
I believe then that we ought to be able to completely relieve him of his puzzlement by offering the following three considerations.
1. First off I'd remind him that, of all people, he knows perfectly well how to use the Glasgow coma scale. He knows perfectly well what it is for someone to be conscious - they can respond to stimuli, are oriented in time and space, can answer questions and so on. In fact he knows about this better than a layperson such as myself because, as a neurosurgeon, he is aware that being conscious or being unconscious is not an all or nothing, binary, matter. There are different degrees of responsivity or reactivity, and he knows what these are.
2. Next I'd invite him to think about all the various nouns which are constructed by putting a 'ness' on the end of an adjective. Happiness, sadness, wistfulness, consciousness, tiredness, egregiousness, greediness, hopelessness, etc. Of these would we not say that the meaning of the noun form is best explicated in terms of a phrase like 'the quality of being X' where 'X' is the relevant adjective? Imagine someone saying 'but we just don't yet know what happiness is!' Wouldn't we want to say 'Well old chap, surely you do know what it is to be happy? It's to be light-hearted, optimistic, have a spring in your step, be of good cheer, lively, etc. etc.' You don't need a scientific or philosophical theory to tell you what happiness is; you just need to have got some kind of elementary handle on the English language. So, here we'd not get troubled about not knowing about the nature of Xness; instead we'd refer ourselves back to the good old tractable adjectival X - by reminding ourselves what the ascription conditions are for being X.
3. Finally I'd want to check in with him that he hadn't accidentally imagined that if we have to do with a meaningful noun then we must here meet with reference and with a referent - with a thing (a substance, entity or process, say) designated by that noun. It's a seductive idea - after all, plenty of nouns do work by referring to entities or processes. Meaning sometimes is referentially secured. But there's surely no reason to generalise such cases. If we did generalise rashly then, in cases for which there really is no obvious physical entity acting as a referent, we're inclined to think there must be a non-obvious one - a mysterious phenomenon of some sort - perhaps a ghostly phenomenon or something like an electrical field or something spookily quantum or... (you get the picture...). Again
|...what happens to your brain when you get|
seduced by referentialist conceptions of meaning
Now I'm not denying for one moment that people who are happy have a range of distinctive endocrine/neurological/physiological profiles. But surely - to return from happiness to consciousness - my interlocutor wasn't saying to me that we don't know what consciousness is in the sense that we don't know what the neural mechanisms are which sustain my capacity to respond to verbal questions, react to visual stimuli, etc. After all, we do know quite a bit about such things! There's surely no more of a mystery about how my being all happy relates to the bodily movements and hormonal secretions and neural activations. (The thing to do is: make sure you don't accidentally think of happiness/consciousness/whateverness as some kind of evanescent end-product of all those bodily goings on! That way you're guaranteed to remain locked in your puzzlement forever! Instead, make sure you think of them as its physiological substrate.)
The appearance of mystery - this mysterious phenomenon called 'consciousness' - is, I'm suggesting, generated mainly by a muddle about how abstract nouns work. It's generated primarily by an over-application of a referentialist conception of meaning. We think, since we can't find a non-mysterious ('physical') entity or process for it to refer to, that the term 'consciousness' must refer to some mysterious phenomenon for which we haven't yet got a good theory. But why think the term gains its meaning by referring to any phenomenon at all? And why think it works by referring punkt? ... As Wittgenstein put it, what we meet with here, at the end of our mystery-busting conceptual therapy, is: 'a whole cloud of philosophy condensed into a drop of grammar'.