Patricia asked:

If Y is the sole necessary and sufficient conditions for X

And if there are no other necessary conditions for X,

And if there are no other sufficient conditions for X,

And if Y is always the entirely subjective belief of any given individual, not susceptible to justification,

Then in what sense can X be said to exist? Or in what sense can the word which is a marker for X be said to have any meaning?

I hope I have phrased this in a way that makes sense. I’m not an expert logician by any means!

Answer by Geoffrey Klempner

Thank you, Patricia, for your beautifully formed question. I would not change a single word of it.

First, I am going to tell you what immediately comes to mind with regard to this ‘X’ (and was probably on your mind too) and then talk about a rather different case which you may not have considered.

What immediately comes to mind? Wittgenstein Philosophical Investigations para. 258 which begins:

“Let us imagine the following case. I want to keep a diary about the recurrence of a certain sensation. To this end I associate it with the sign “S”…”

From around para. 200 onwards, Wittgenstein has been leading up to this, his case against the notion of a ‘private language’, a language that purportedly refers to subjective ‘objects’ such that ‘a definition of the sign cannot be formulated’. This last bit is crucial, because although we normally consider things like pains and tickles to be subjective or private, these events exist in the arena of public discourse, with repeatable and recognizable causes and effects.

‘S’ is different. Apart from my writing ‘S’ in my diary, nothing physical changes in me to prompt the writing of ‘S’ nor is there any characteristic external behaviour for S, nor any physical event that can be observed to cause me to write ‘S’.

By the end of para. 258 the argument is already over. Game, set and match. (I’m not going to go over this here, books have been written about it.) All that follows are objections that Wittgenstein bats away with ease. The idea of ‘belief’ is the very first thing he considers, in para. 260:

“Well I believe that this is sensation S again.” — Perhaps you believe that you believe it!

What is it to ‘believe’ something, or ‘believe in’ the existence of something? Our first thought is that ‘I know what I believe’. The fact that I believe that P, or believe in the existence of X, is self-validating. I know what my beliefs are, a priori. So what, exactly, is it that presents itself to my mind when I have a belief that P, or a belief in the existence of X?

There are things one can say about many beliefs that are not true of all beliefs. For many beliefs, there is evidence that one would point to; but not for all beliefs (e.g. the belief that the universe has existed for more than 5 minutes, Russell’s famous sceptical hypothesis). For many beliefs, there are actions that are appropriate if you have that belief, but not for all beliefs. Let’s say that (for whatever reason) I believe that Donald Trump will be remembered as one of the great American US Presidents. There is nothing that I can do to show that I have this belief other than asserting that very statement, or repeatedly Tweeting it, or saying (in 8 years time after Trump’s second term) ‘I told you so!’

This ‘sensation’ that I’m having now, which I call ‘S’ is one I ‘believe’ I’ve had before, when I first gave it the name ‘S’. What makes this a case of belief? We’re all familiar with that feeling you get when you recognize something or someone. ‘I’ve seen that car before, what is it?’ ‘It’s a Pagani Zonda.’ ‘Ah!’ Problem is, the ‘feeling’ I get when I ‘believe’ I am having S again is just another incorrigibly subjective feeling, like S. Maybe I’m just imagining it all. What is the difference between ‘belief’ and ‘imagination’? Like cases of deja vu, where you really can’t say exactly what is in your mind or what you’re thinking.

In short, the appeal to belief doesn’t help. It doesn’t go a single step towards weakening the case that Wittgenstein has made in para. 258.

— Now, I want to consider a seemingly very different case, or rather cases, of your ‘X’.

Here are two examples. I believe that I have a guardian angel. I also believe that I have a virtuous soul.

Because I have a guardian angel, whatever bad things may happen to me will not be as bad as they would have been had I not had a guardian angel. If I break my arm, then I can console myself with the thought that were it not for my guardian angel, I would have broken my arm and my leg.

Similarly, I may have done some despicable things in my life, but I believe that because I have a virtuous soul, these were aberrations, the result of ethical misjudgement, rather than reflections of my true character. Were it not for my virtuous soul, I would have done far worse things.

I believe that I have a guardian angel and a virtuous soul because I really do have a guardian angel and a virtuous soul. I have these gifts because I believe it and only because I believe it.

Moreover, unlike the case of ‘S’, these beliefs definitely have consequences. Because I have a guardian angel, I am prepared to take risks that I otherwise would not have taken. Because I have a virtuous soul, I am prepared to put myself in moral danger that I would not otherwise have put myself in.

Wouldn’t this be a case that fits your schema? We can go further and generalize. I could believe these things about you. Because you have a guardian angel, your question was more cogent and logical than it otherwise would have been, etc. (So this isn’t, as one might have first thought, merely a case of ‘self-fulfilling prophecy’.)

Over to you.