2. A Hunch

I begin with a hunch, based on years of teaching Descartes's argument to university students. The hunch is that if one cannot know that other people will agree that one knows the world then one has lost a substantial emotional defence against an argument such as Descartes's. Think of Franz Kafka's grippingly repellent 1925 novel, The Trial – a tale of one man recognizing bewilderedly his increasing social isolation even in the midst of much, indeed unceasing, social activity. Think of the 1998 film The Truman Show, where Jim Carrey's character is unwittingly living a life that has always been merely a role in a TV show – with everyone around him wittingly playing a role in that same production, the whole enterprise designed to deceive him so as to entertain a TV audience. In short, think of the variety of ways to lose the social support that seems usually to be provided by other people. So much more is also lost – perhaps a sense of one's self, the knowledge of one's own mind. And then, I suggest, one sinks into Descartes's grip – descending into his potential epistemic hell. At that point, it seems, the thought that one does not know that one is not dreaming is frightening.

But first – before entering Descartes's epistemic hell – comes the loss of one's relevant social bearings. Epistemologists present Descartes's dreaming argument as having a kind of intellectual priority – a challenge that properly precedes all associated challenges. And yes, it can be viewed in that way: ‘I do not know that there are human bodies, let alone ones agreeing with me, if I do not first know that I am not dreaming their presence. I do not know a world around me, if I do not first know that I am not dreaming its presence and nature.’ Psychologically, however, I am less sure about that priority claim. It has long seemed to me that students take marked and continuing reassurance, upon first hearing Descartes's argument, from the prior confidence that they are hearing it as a group – and the associated confidence that this puts them in an epistemically strong position to reject the sceptical argument as a group. Possibly an individual here or there succumbs to its wiles. But the social majority within that setting feels vindicated – as social majorities so readily do – because it is a social majority there. Thus we have a manifest lack of real angst in the classroom: intellectual ferment, maybe; real fear, no.

Hence, we should ask how an epistemologist could, on behalf of a sceptical argument, undermine that groupthink (as it might be). How should we ask a student to lose her social bearings, before exposing her to the dreaming argument?

3. Some Brutal Teaching

Here is how. A teacher could direct the following questioning at a specific student:

Most likely, some of the other students will raise their hands – denying energetically that they would lie in that way, affirming their being supportive. But this teacher is unruffled. Imagine her continuing in this way, still looking at you:

The teacher also asks whether it is possible that – without your having noticed this about yourself – you are far less intellectually capable and intelligent than the other students:

The teacher is relentless – and seemingly unfeeling – in conveying these brutal thoughts.

4. Cartesian Aloneness

That challenge asks a single person to feel like a single person – deeply and irreparably single. She confronts the possibility of being alone in a fundamental way – isolated, friendless, beyond all social assistance when seeking knowledge, indeed among epistemic enemies. We might say that the teacher is trying to make the student feel more like how Descartes claimed to be in his Meditations – on one's own when confronting sceptical doubts.

Again, part of the interest for me in describing this sceptical challenge rests upon an apparent observation from my years of teaching. What is widely noticed by philosophers is that, when the Cartesian dreaming possibility is proffered to a classroom, usually no one loses emotional confidence in being fundamentally safe from the described possibility: rarely, if ever, does someone feel a real threat to most or all of her beliefs about the surrounding world being trustworthy, true, and knowledge. But it has long seemed to me that part of why students remain so confident on such occasions is their assuming (without the issue being raised explicitly) that, because they hear the challenge as a group and can talk with each other about it, they thereby survive it as a group. An apparently equally shared problem is no problem at all (it seems that they will feel): if all are equally affected, then none is affected, not in any way that should make anyone anxious. And apparently – judging by how it is standardly presented by philosophers – the challenge is about people in general. Each student looks around the room, comforted by seeing everyone else: ‘I could not be in any danger, because we could not all be so.’ I suggest that such thinking (even if presupposed rather than explicit) might well be enough, in the minds of most students, to allay genuine fear at what could otherwise be … alienating and unsettling.

So, the possibility I am raising for a single person – being an epistemic island, entire unto herself, with the waters rising, rising, ever rising and enveloping and isolating, even while believing herself to be among other people – aims to remove that potential reassurance. Philosophers generally describe the Cartesian picture in ‘Meditation I’ and ‘Meditation II’ as a case of epistemic solipsism: an individual's not knowing any reality beyond herself at that moment. But the irony in this categorization is that, when we teach the standard Cartesian predicament to students, ipso facto – precisely because we are interacting with them as a group – we can do nothing to establish a felt sense of epistemic solipsism within each student in that room. The teaching is itself an activity that – by being directed overtly at a group, singling out no particular individual – counteracts the experiencing of solipsism by any particular person in the room. This undermines the likelihood of Descartes's sceptical reasoning having psychological impact in that setting. We teach to a group, whose members engage as a group with the issue, typically encouraging each other – and who never, in my experience, move as a group against some single person among them. Never do others in the room single out one unfortunate student, in the way described by the alternative scenario that I am envisaging.Footnote ¹ But imagine that happening. This would dramatically change the room's sceptical dynamics. Suddenly, the sceptical reasoning would be alive: threatening, not merely puzzling; emotional, not merely intellectual.

5. Home Alone, Reading

Section 4 was about a single person who – even within a crowded classroom – can be made to feel alone and vulnerable in an epistemic way. But consider someone who initially encounters the usual Cartesian challenge by reading it on her own, away from a classroom. She could be alone at home, opening the Meditations for the first time. She is not enmeshed in the socially supportive atmosphere of a standard philosophy classroom. Still, it remains probable that the usual Cartesian challenge – built around the possibility of her dreaming while taking herself to be experiencing the world normally – will gain no psychological grip upon her.Footnote ² And this cannot be because – home, alone – she is able to look around a room of epistemic peers, all or most of them confident of knowing the world and willing to include her within their comforting group in that respect. This source of epistemic reassurance is absent for her. Why, then, wouldn't she be emotionally unsettled by the Cartesian possibility when meeting it in this setting – cloistered and apart?

Imagine being that person. There is a relevant way in which you would not be so isolated in that setting. You would be confident of soon rejoining the wider social world – melding into overlapping communities of people ready to concur with you and to impart their knowledge. You would realize that you need only to walk into another room, or to await a new day with its social opportunities, to be among epistemically supportive peers. So, you remain part of that group in an extended or implicit way – regardless of where you are at a given time. Accordingly, the Cartesian dreaming possibility – even when you are alone – will seem like a mere passing fancy within what is overall a steady stream of socially experienced and reinforced normality for you. Not for one moment do you feel really alone in this respect. Yet imagine believing suddenly and inescapably that everyone else in the world had been destroyed in the past five minutes, while you were quietly reading Descartes's Meditations at home, alone. In that event, I suspect, you would suddenly feel more deeply alone: you could no longer feel part of the larger community that you now take for granted.

But even if that apocalyptic belief never comes upon you, section 3's posited possibility should again be with you – the possibility that to rejoin a social world is to enter anew a world of untrustworthy and uncaring people. They would be like that in how they treat you, at any rate. And somehow they would hide from you this underlying unwelcome reality. It would be a world of people happy to mislead you (even when professing otherwise) whenever they believe themselves to have knowledge of the world. They would keep the knowledge for themselves, not sharing it with you. It would be a world of people who also do not care whether they are misleading you when they are not confident of having knowledge.

Surely all of this is possible. How could you ever know that it is not happening to you? How could you not be perturbed – really upset – about being unable to rule out that possibility?

6. Even More Unwelcome Questions

So much so, that the following questions arise. Could madness lurk around that unhappy corner? Does a form of paranoia – even if a mild case – attend such thinking? What of unhappiness? Perhaps so – for each of those questions.

The sceptical argument being proposed here takes shape around a phenomenon that is part of many people's lives – one that is experienced very consciously, rarely being discussed with others when being experienced. For many people, the possibility of not ‘fitting in’ with others’ perceptions – of ‘standing out’, ‘seeing the world differently’ – is an ever-present fount of anxiety. ‘Am I different? Will everyone notice my being so different? I don't want to be different.’ There is no news in being told that this fear is often present in childhood and adolescence. It can persist throughout adulthood. The fear can live within one's self-consciousness for minutes, hours, days – longer. And a person could know all too well – with sadness, frustration, fear – its presence within herself. Contrast that phenomenon with dreaming – the experience at the heart of Descartes's dreaming possibility. At any given moment, it is possible that one is dreaming; yet rarely is this possibility an existentially worrying one. But being ‘apart from’ others, not being cared about by them, being misled by them, being lied to by them: this is the stuff of existential angst. Even to think that it might be happening in undiscoverable ways, day after day after day, could leave one feeling vulnerable, prey to those fears.

Hence, once more, this article's sceptical questioning arises. At any time, how can you know that you are not being treated by others in that way – being spurned epistemically, being given no support by them as companion believers, perceivers, and thinkers? At any time, how can you know that you aren't being viewed by others as not deserving to be told the truth? At any time, how can you know that – beneath what might be an appearance of civility and support – others aren't viewing you as a fit recipient of untruths and of stratagems designed or liable to mislead you? Our sceptical argument says that you never have that minimally reassuring knowledge of your being part of an epistemically supportive social world.

Maybe the article's sceptical argument is ultimately answerable; I have not argued that it isn't. Even so, the argument deserves to be discussed as a sceptical challenge, partly because it has a psychological depth that is frustratingly absent from generally discussed challenges such as Descartes's dreaming argument.

7. Aloneness Scepticism

This article's challenge is built around an aloneness possibility. So, I call the challenge the sceptical aloneness argument and worry. Descartes gave us the sceptical dreaming argument – but not an emotionally real worry. The sceptical aloneness argument, it seems, is also an emotionally real worry (at least until it is ever undone by epistemological counterargument).

Many contemporary philosophers regard Descartes's argument as an intellectual worry. And (as section 4 indicated) this is partly because they treat the argument as universalizable – rather than as simply a single clever person (Descartes) having intellectually puzzling doubts about himself. It is usual for philosophy teachers to introduce a sceptical argument like Descartes's as questioning ‘our’ having some kind of knowledge – a challenge to all if even one of us. From the outset, each of us is said to be implicated – with one sweeping consideration or argument. We are – or are not – in that predicament together, vulnerable – or not – as a group. This is so, both for students gathered in a room and for an individual reading a book on her own. ‘Consider this sceptical argument about whether we have external world knowledge’: that is a typical first sentence – note the use of the word ‘we’ – used in introducing a sceptical argument such as the Cartesian dreaming challenge.

Yet (in line with sections 4 and 5) we now see why that way of introducing a sceptical argument – even in writing – can be a reason why individuals do not feel so vulnerable at such moments, either hearing or reading the argument. That way of introducing the argument embodies a presumption that the argument is inherently universalizable in scope and intent; which (from sections 3 and 4) could already be enough to engender both the individual and the collective anti-sceptical confidence that we cannot all be failing in the hypothesized way – hence that no one of us fails. If others are reassuring you, then (you will feel) they are to be trusted; and so you cannot honestly feel at risk, in the sense of feeling threatened. Instead, you feel safe: you are protected by being part of a larger intellectual polis. But your right to have such a feeling in the first place is being questioned by aloneness scepticism. It would be realistic, but also sad and disorientating, for you to wonder whether everyone is trying to deceive you, or whether they agree with you only because they don't care about being correct in what they say to you.

I don't in fact think that people typically do this to me. It is a realistic possibility, though; and on a given day – perhaps more at some times of life than at others – that circumstance might feel real, not simply realistic. If one's aim as a philosophy teacher includes one's encouraging students not only to see intellectual intricacies inherent within a sceptical challenge, but also to feel emotional urgency at the idea of not disposing of that challenge in an intellectually adequate way, should aloneness scepticism be introduced into some classrooms, in the active and psychologically real way described here? In principle, yes – although presumably each of us, if only from human kindness, would be loath to do so.Footnote ³