Here it is:

Not so great? David Stove called it ‘the Worst Argument in the World’.Footnote ² Not a big fan of last place – even when it comes to my fellows – I want to shove it in reverse and double back: Berkeley needs a champion. The strategy is all defence: I'll try to dodge the blows of the critics. If the argument holds up under fire, it's not the worst. The man's not going to get a medal for his entry – granted. But he's not a disgrace. That's the prize I'm after. Greater glory can wait.

Curtain up. Let's crack this thing wide open: Berkeley's master argument has the highly practical aim of proving that nothing exists. Quatsch! That was freestyling. Rather, it's an argument for immaterialism purporting to show that we can't even conceive the existence of matter – a completely mind-independent substance. (In case you missed the briefing: immaterialism is the view that matter does not exist.) For, to conceive of the existence of matter in this sense would be to fancy something existing unconceived. But aren't we conceiving it while we fancy?

There you have it. That's the argument. Case closed? I'm thinking: kick the tires before we buy.

The most acid opposition, and by far the most annoying, comes from A. N. Prior and George Pitcher – authors of the celebrated ‘quantifier shift’ and ‘conflation’ objections, respectively. I submit that both are duds, and for the same reason.

Prior debuts against Berkeley in 1955 with a wretched little paper called ‘Berkeley in Logical Form’.Footnote ³ James Van Cleve – no slouch – prunes the twigs from Prior's busy argument and gives us the following simplified version of the quantifier shift:

There's no arguing with logic, and if Berkeley does in fact slip his quantifier to the west side of the ‘C’, then he's a cups-and-balls magician who deserves the ‘philosophy of thrashing’ recommended by Lange in 1723.Footnote ⁵ Less theatrically, the point is this: Berkeley apparently transfers the evident inconsistency involved in conceiving of this thing existing unconceived – there I am conceiving it all the while – to the perfectly coherent act of conceiving something or other in general existing unconceived. The first is an operational self-refutation.Footnote ⁶ In supposing ‘there is a tree about which I suppose that it exists unconceived’, I conceive the tree.Footnote ⁷ Just as you ruin the game by saying, ‘The golden mountain does not exist’, so you crowd yourself into the frame when you try to imagine some particular thing existing unconceived. It's a bit like taking a photograph of your dog in the yard and then noticing your reflection in the window.

By contrast, ‘I suppose that there is a tree which exists unconceived’ won't spring the trap. Notice the position of the quantifier in Van Cleve's formulation: C(∃x¬Cx). You're going to trip on it: ‘the existential quantifier is a barrier to my supposing's giving of the status “conceived” to any tree so introduced’.Footnote ⁸ Berkeley's fatal error – resulting in philosophical infamy and a permanently shaky reputation – was to tear through the barricade and conceive the x. Blind to the seismic gap between ‘there is an x that I conceive’ and ‘I conceive that there is an x’, he ranked the latter with the former and called it quits – a model of stupidity, we must suppose.

The second objection is a variation on the theme. Pitcher makes a big show of this in his Berkeley Footnote ⁹ – adverting to a play about Robinson Crusoe – but Alasdair Richmond crams it all into a ZIP file: the master argument ‘conflates the representation (the idea presented to consciousness) with the represented (the thing the representation depicts)’.Footnote ¹⁰ Maybe I'm on the wrong team. Running representation and represented together is as childish an error as mixing cola in a highball. ‘A learned fool …’ I'll get back to that.

What Pitcher seems to be getting at is this: Berkeley mistakes the thing he's thinking about for the thing he's thinking about. That probably needs some touching up. Let me give you an example.

Suppose I'm contemplating some particular plant: a fern, a bramble – take your pick. I have a plant, actually. It's called a ‘lemon drop’. (No kidding. Tall thing.) Now let's say I'm trying to cut this plant loose. I send ‘lemon drop’ out in the world – stand on its own two feet and all that. I'll imagine it taking chambers in my neighbour's rental. (You know, now that I've said it … Current tenants? Bottom rung.) Anyway, we'll settle for a shabby room on the upper level – quite isolated; no view. (Just give me this example: I'm working with limited funds.) Envisioning that plant now in its new surroundings … no connections … lots of ‘down’ time … Ah, tommyrot! There's me thinking of it again. That's the ‘operational self-refutation’ we've been trying to shake. Berkeley's ‘master’ stroke, as it were: you can't get the perceiver out of the image.

Enter Pitcher: No, ‘lemon drop’ is there on her own. Your idea of the plant is in your mind – the representation. That's basic metaphysics. But the plant itself – the represented – has relocated. It's next door trying to make rent. Representation: in the mind. Represented: in the world. Goodnight, Irene.

You weren't hoping that I'd disagree with Pitcher, were you? I mean, I've got a lot on my plate right now. There's only so much I can do.

Truly, things are not looking rosy for my thesis. But as my father used to say, the best way to avoid a haymaker is to duck. So here goes: Berkeley says ‘or’. (Remember: You saw it here first.) He says it in the Principles and he says it in the Dialogues. So he means it. And it's not like I'm crawling down a limb in supposing that the words were vetted carefully, since he bet the farm on this little demonstration.

I appeal to the libretto:

Now let me take a swing at this. What to make of the either … or? I assume that by either … or Berkeley has in mind something along the lines of: either one thing or another. That's at least a thinkable interpretation. Yet it doesn't seem to have been given much of a hearing. Basically we're done, but since I don't have anywhere to be – ever – I'll connect the dots for you.

Prior accused our hero of conflating (1) conceiving of some particular thing existing unconceived, with (2) conceiving of something or other existing unconceived. Pitcher laid similar charges: Berkeley conflates (1) conceiving the representation existing unconceived, with (2) conceiving the represented existing unconceived. As I see it, the bishop is too cunning for that to stick. Far from washing the lights with the darks – far from letting his (1)’s bleed into his (2)’s – Berkeley does separate loads. If you try to conceive matter by doing (1), you get a contradiction (an absurdity, an operational self-refutation); if you try to conceive matter by doing (2), you get nothing (words without a meaning). Either … or. Consult the text.

As for the (1)’s, when I try to conceive of some particular thing existing unconceived – some particular thing I'm representing – I detonate myself by conceiving that thing, the particular representation. When I try to conceive the (2)’s – something or other existing unconceived, something referred to by my idea, something represented – I'm shooting blanks. Sure, I can say that I'm conceiving of something or another existing unconceived, or something referred to by my representation, but then Berkeley would be well within his rights to ask: What are you conceiving? Tell me about it. I'll find myself at a loss (a familiar situation). I can't produce details – short of repeating my words – without calling in images of something spatial, something coloured, something figured, etc. But those are images of previous sensations – they are ‘potential experience[s]’, as Gallois nicely puts it.Footnote ¹¹ And images of previous sensations are smuggled goods, for Berkeley, since he wants to rule out matter conceived as a totally mind-independent substance, something free of sensations altogether – actual or possible. Seeing as I took my doctorate at a café, I have no reservations about this construction: We can't supply the thought with any intuitive content. Yes, I have the term ‘matter’ in my wallet, by which I mean a totally mind-independent substance. ‘Fair enough’, Berkeley would say, but your thought is empty. So either you're contradicting yourself, or your words are hollow: ‘and how nearly this comes to the description of a non-entity, I desire may be considered’ (Principles, 68). I desire that too.

The drama continues in the legendary Dialogues between Hylas and Philonous, mentioned previously (first run: 1713, Common Era). Wrapping up the resistance in the last act of the second, Berkeley's antagonist, Hylas, calls a split decision: Philonous – Berkeley's man – may have spotted an inconsistency in the everyday sense of ‘matter’: ‘an extended, solid, figured, movable substance existing without the mind’ (sense (1)). A hat, say, is a walking contradiction, if we're talking non-phenomenal hat. A hat in itself is repugnant. It's made of ideas, for one thing. And aren't you thinking about it, for another? The perceiver walks in on the hat while picturing it there in the closet. Hylas is sporting on the point: ‘True, but that is only one sense of the term “matter” ’ (Dialogues, 2). Philonous grabs the mic: ‘can any more be required to prove the absolute impossibility of a thing than the proving it impossible in every particular sense that either you or anyone else understands it in?’

Never shrinking from a scuffle, Hylas comes out punching: ‘I am not so thoroughly satisfied’. Wasn't Philonous hired to prove the impossibility of matter in every sense, including ‘the last most obscure abstracted and indefinite sense’ (Dialogues, 2)? Is this a breach of contract? The something or another sense of ‘matter’ – (2) from above – can surely be thought without contradiction.

Smelling a rat, Philonous puts it to him squarely: ‘You are not … to expect I should prove a repugnancy between ideas where there are no ideas, or the impossibility of matter taken in an unknown sense’ (Dialogues, 2). There is no inconsistency – no operational self-refutation – in the notion of a something or other in general existing outside of minds. But there is also no content. That's why Berkeley says ‘or’: ‘Matter’ is either ‘an absurdity’ (self-refuting) or it is nothing (void of content). No foul there.

You give it a try. First prong: ‘I'm thinking about it but not really thinking about it!’ That's laughable (like when a toddler hides by shutting her eyes). You stepped on your own foot. Second prong: ‘I'm picturing it, but not in terms of ideas’. That's a total scam (like meditation). You can't think about nothing. I suppose you're getting the drift.

I'll be the first to admit that there are better arguments on the market. How about this one that I found in a logic book?

1. 1. P and Q.

2. 2. Therefore, Q and P.

That's pretty good. Unbeatable, really. (I'm picturing this in action.) More to the point, though, is that there are worse arguments in the world. Berkeley himself peddled a few. The perpendicular growth of plants, he argues, disproves the universality of gravity (Principles, 106). That's worse. Then there's his comic claim that occasional miracles might be necessary to ‘surprise and awe men into an acknowledgment of the Divine Being’ (Principles, 63). Awful. (Come to think of it, you should read my master's thesis.)

The argument we've shortlisted here is of a different order. Notwithstanding the low-budget presentation I've tossed together, I hope it's clear that Berkeley is making a serious philosophical point capable of disrupting the leisure hours: a thing in itself – I mean really in itself – is just a placeholder, an empty shell that can't be grasped. A naught. A limit – sounding a bit German? I think so too. Full-blown immaterialism is a radical thesis. I'm not planning to go Lewis and try to prove it (I don't have the talent).Footnote ¹² I'm not going to tell you that Berkeley's arguments are any good (most of them are rubbish). The long and short of it, though, is that the master argument is not the stinker it's always made out to be. Far worse arguments have done the rounds in the history of philosophy. Much weaker stuff is hatched and sees the light of day – it happens as we speak. I wouldn't tell you where to place your money. I wouldn't tamper with the votes. But spend an evening with the master argument – the metaphor is clean – take the telephone off the hook. I think you'll see a grain of truth that will move the cogs and springs. And when you boil off the fat, that's what pays the bills: Think!