January 21, 2021

When I was an undergraduate, I had a strange recurring dream: What if I was the only person in the world? I imagined a reality in which every person I encountered was merely a prop in some elaborate masquerade designed to fool me that other humans existed. In this world, when the people were out of sight they would just stop, motionless, like machines that had temporarily performed their function.

The dream tended to be structured around me trying to catch them out. I would stand at the corner of a building and very quickly stick my head around the corner – quickly enough, I hoped, to find them still motionless, surprised by my stealth. But they were always too quick for me, always one step ahead. I could never expose this plot. But nor could I discount the possibility that it was nonetheless true.

This strange dream was, I suspect, partly inspired by a woman I met in Hinchingbrooke Hospital, where I helped out on the psycho-geriatric ward during my university holidays. The woman in question believed that her body was hollow and completely filled with urine. She would only sleep upright, for fear that she would drown. When encouraged to lie prone she would begin to panic, coughing and spluttering, with genuine fear in her eyes.

It wasn’t that she was stupid; in fact, far from it. She was still able to complete The Times’ crossword, for instance. But however much I tried to reason her out of her belief – genuinely held, I was convinced of that – she had a considered response. It drove me to distraction that I wasn’t able to find a way through her inter-locking explanations. Surely reason could expose such an obviously mistaken view of the world? But as hard as I tried, I was never able to puncture it. At turns angry and frustrated, I eventually gave up and spent my days holding her hand and talking with her about her grandchildren.

Both of these memories returned to me after reading Freddie Sayers’ recent piece on the importance of scepticism. He was, of course, completely correct that to uphold a critical approach that requires us not to accept arguments on face value. But what happens when scepticism starts to challenge the very fabric of our lives, when it becomes so all-consuming that even the generally agreed mechanisms of explanation are themselves called into question?

The careful, methodical, empirical steps of the scientific method were unconvincing to the woman who believed she was filled with urine. She was surrounded by scientific equipment and various monitors. But all of these were a deception, she believed. In colloquial terms, we generally describe those who are distanced from rational explanation as “mad”. But to reach for this word hardly solves the matter.

Yes, many brilliant people are called mad when they first question received authority. But it is also the sort of thing said by conspiracy theorists the world over. From people who think lizards control the world to those who believe the Covid vaccine is a way to implant microchips, the language of scepticism is often employed to justify their doubt that things are really as presented. “You don’t question things enough,” they say. “You are too credulous.” This is both the language of genuine intellectual inquiry, and yet also that of the mad and the bad.

Scepticism turns out to be a remarkably tricky business. Generally speaking, we imagine some boundary beyond which scepticism should not pass, or some format that limits the sceptic’s operation. For Freddie, that format is the scientific method. But there have been many who would even apply scepticism to that methodology. And indeed, if we challenge the scientific method to justify itself, we might reasonably ask that it does not do so in its own terms: the scientific method cannot supply its own justification without circularity.

Something other than itself is required as a means of justification. And this introduces the idea that, with radical scepticism, the questions never end. As Wittgenstein famously asked, at what point is the spade turned, and solid ground is revealed? At what point do the questions run out? Steady on, we say. There must be a point at which the questions end. But isn’t this precisely the kind of limit about which the sceptic complains?

You may think that these questions are a bit odd. Indeed, they are. And I will return to that. But it is worth noting that modern philosophy begins at precisely this point. Most university philosophy courses begin with Descartes and his methodology of radical doubt. Doubt anything that can be doubted, he argues, and see what survives. His famous answer to this was that the only thing you have left is the “I” – even when you doubt something, there has to be something doing the doubting. Doubt requires a doubter. Cogito, ergo sum. This is one of the most influential sentences of modern thought. And it is because modern philosophy begins at this point that the “oddness” of radical scepticism begins.

Because, whether or not you agree with Descartes, the Cogito method still leaves a lot more to establish, not least the existence of other people beyond myself. I may know I exist. But do I know that you do? Descartes used God to fill that gap. He believed that God, whose existence could be rationally demonstrated, would not deceive us, therefore guaranteeing a kind of bridge from my existence to that of others. But, in time, the God answer proved to be unconvincing. I suspect this was what was behind my dream. I had been reading too much Descartes and swallowed his methodology of radical doubt. Through the lens of his universal scepticism, the world seemed like a very odd place indeed.

To complicate matters, there are occasions where we can’t really know another person’s thoughts and feelings. I currently have a headache. But others may suspect I am claiming to have a headache to get out of the washing up – and they have no way to check if I am telling the truth. My pain is not accessible to others in ways that make Descartes’ challenge about the existence of other minds seem credible. At the very least, it feels like the basis on which radical doubt may have some purchase. This is why thinkers like Wittgenstein talk a great deal about pain.

Can radical scepticism be refuted? The person who, to my mind, has done most to examine this question is the American philosopher Stanley Cavell, who passed away a few years ago. Cavell thought the sting of scepticism can be removed, but not using Descartes’ framework. He argued that Descartes began in the wrong place and so set off on an impossible quest. For Cavell, the constant “how do you know?” of the radical sceptic is a question that is in search of the wrong sort of answer. This is because human beings do not begin as individual units, ontologically distanced from each other. Our individuality is a derivative concept, one that takes shape over time.

Instead, the original basis for human life is community; or, at least, a sense of togetherness. The mother breastfeeding her child is in no doubt that her baby exists, and nor does it make any sense for the child to doubt the existence of the mother. Doubt, if it enters the picture, comes much later. What comes first is not a kind of intellectual certainty about others, but an implicit acknowledgement upon which everything else is based. This is crucial. Doubt and scepticism only make sense if there is an already basic understanding of human identification. We begin with the acknowledgment of others – and only after that do we begin to ask whether, for instance, a person is telling us the truth about their inner life.

In other words, the problem with my dream was that it converted something that is constitutive of the human condition, our living alongside others, into a hurdle that needs to be overcome intellectually. To put it simply: in real life, trust necessarily precedes doubt. Not a credulous trust in arguments that demonstrate the other’s existence, but a recognition that something other than intellectual arguments is the basis of human solidarity.

All of this may seem unnecessarily abstract. But, in fact, it can be remarkably straightforward. As Freddie rightly points out, David Hume acknowledged that “amidst all of your philosophy, be still a man”. In other words, scepticism is a human activity and one that must operate on the basis that common humanity provides. Too many thinkers, and philosophers especially, have not appreciated the wisdom here, and have tried to construct all knowledge on the basis of reason alone.

For all its apparent attractiveness, this way madness lies. For without this basic acknowledgement of shared humanity, nothing can ever be known with certainty. And this opens up a gap between the day-to-day operation of human life — chatting in the street, going about our shopping, even making love — and the increasingly bizarre questions that philosophers ask each other. To quote Hume at length:

“Where am I, or what? From what causes do I derive my existence, and to what condition shall I return? … Since Reason is incapable of dispelling these clouds, Nature herself suffices to that purpose, and cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation, and lively impression of my senses, which obliterate all these chimeras.

“I dine, I play a game of backgammon, I converse, and am merry with my friends. And when, after three or four hours’ amusement, I would return to these speculations, they appear so cold, and strained, and ridiculous, that I cannot find in my heart to enter into them any farther.”