Radical skepticism and the non-affirming negation: a summary

"Reality is that which, when you stop believing in it, doesn't go away." -- Philip K Dick

Radical skepticism

Young earth creationists believe that the earth was created in the past ten thousand years. The Omphalos Hypothesis points out that dinosaur bones and other seemingly old artifacts might have been planted there by God as a test of our faith.

As ludicrous as this may strike you, there is no logical contradiction in it. In fact, there is no way to disprove that the universe sprang into existence, fully-formed, last Thursday. Bertrand Russell takes it one step further:

"There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that 'remembered' a wholly unreal past."

Taken to its logical limit, this may all have appeared freshly in this very moment. But while such a claim is not logically impossible, it is certainly very improbable. Right?

Well, stop for a moment and consider how you might evaluate such a probability. Suppose you have two models to choose from: one in which everything suddenly appeared exactly as it is now (let's call this the Russell metaphysics), and the other is the default model of materialism. What evidence will you use to decide in favor of one or the other?

Any facts about the world are fully compatible with either model. As such, they should not bias you toward believing in one or the other. As an example, suppose you are trying to determine whether an unseen coin is a nickel or a quarter. If you are told that it was flipped and came up heads, this shouldn't cause you to favor either answer. Even if you were told it has been averaging 50% heads over the last thousand trials, then (assuming both coins are fair) you still have learned nothing. You need evidence that differs in the two cases, and we've purposely constructed Russell to be identical in appearance to the materialism.

You may try to use something like Occam's Razor to make a case, but even here you must be careful. If your argument takes into account anything from the past -- such as evidence demonstrating that Occam's Razor is valid -- then you are assuming your metaphysics in order to prove it. This is circular reasoning, and clearly invalid. If you use Occam's Razor in its aesthetic form (namely, that simpler models are more beautiful and thus preferable), then you are not stating a probability but a preference.

Nonetheless, it is such an incredibly strong preference that it may be hard to recognize as one. The existence of a past is an assumption with no logical justification. Doesn't that statement rankle you?

It almost certainly does, and this is itself enough to give you a good reason to stick to your default metaphysics. Russell himself refused to take radical skepticism seriously:

“Skepticism, while logically impeccable, is psychologically impossible, and there is an element of frivolous insincerity in any philosophy which pretends to accept it.”

Same with Hume (whose brilliant Problem of Induction similarly destroys the supposed evidence for a sane-looking future):

"Should it be asked me whether I sincerely assent to this argument which I have been to such pains to inculcate, whether I be really one of those skeptics who hold that everything is uncertain, I should reply that neither I nor any other person was ever sincerely and constantly of that opinion. I dine, I play backgammon, I converse and am merry with my friends and when after three or four hours of amusement I would return to these speculations, they appear so cold and strange and ridiculous that I cannot find in my heart to enter into them any further. Thus the skeptic still continues to reason and believe, though he asserts he cannot defend his reason by reason."

And finally, modern physicist Sean Carroll:

“There is no way to distinguish between the scenarios by collecting new data. 

What we’re left with is our choice of prior credences. We’re allowed to pick priors however we want—and every possibility should get some nonzero number. But it’s okay to set our prior credence in radically skeptical scenarios at very low values, and attach higher prior credence to the straightforwardly realistic possibilities. 

Radical skepticism is less useful to us; it gives us no way to go through life. All of our purported knowledge, and all of our goals and aspirations, might very well be tricks being played on us. But what then? We cannot actually act on such a belief, since any act we might think is reasonable would have been suggested to us by that annoying demon. Whereas, if we take the world roughly at face value, we have a way of moving forward. There are things we want to do, questions we want to answer, and strategies for making them happen. We have every right to give high credence to views of the world that are productive and fruitful, in preference to those that would leave us paralyzed with ennui.”

In other words, you should believe it because it is psychologically comforting. Leaving aside the obvious parallels with religion, we should consider whether there is an alternative that these great thinkers have missed.

Layers of thought

Have you ever had the experience of reading a book, only to discover that your eyes are still scanning the page but your mind is elsewhere? If you're interrupted mid-reverie, chances are you can recall the past few seconds of thought. Those thoughts were not really outside your consciousness and yet, somehow, you didn't notice them.

Chances are, you spend the vast majority of your day in a state where you're thinking without being fully present in your thoughts. The mind readily back-fills a sense of presence, so that you can easily convince yourself that you were present when you weren't. If you want to test this yourself, just sit down and pay attention to your breath. See how long it takes you to be distracted, and how long it takes you to notice that you are distracted. You probably won't catch it immediately, even when your whole being is engaged in the effort. What of the rest of the day?

If you decide to progress on the path of meditation, this starts happening less and less. As you become more present, you detect an undercurrent of more subtle thoughts between the big, coarse ones. When even these quieten, and you're sitting in a seemingly thought-free state, you might consider yourself basically free of thought.

But are you?

If you still feel like a self sitting in a world of space and time, it's because there's still a layer of your mind you have not yet penetrated.

If you look carefully enough, you will notice that your mind is taking experiences and subtly weaving a narrative from them. Memory implies a past; anticipation implies a future; together they imply time and a self. Vision and touch together imply space and matter. Etc. The sense that the past contained a physical world bolsters the certainty that this moment must, too, and that there will be moments to come, following a fairly predictable trajectory. This narrative becomes the "background" of your experience -- as though it were given to you, rather than you fabricating it.

In brief, the world feels mundane. These assumptions are so deep that they stop feeling like assumptions and start appearing as tangible, palpable, externally imposed structures. I mean, isn't it viscerally obvious that time and space are real, and not merely assumptions? Well, that feeling is there because you are continually reinforcing it (leaving aside for now the question of what "continuously" means in a world with no time). You do it because it's psychologically comforting. And like with distracted reading, it simply escapes your notice.

Hume's positive view is that the experience of constant conjunction [things happening together] fosters a “habit of the mind” that leads us to anticipate the conclusion on the occasion of a new instance of the second premise. The force of induction, the force that drives the inference, is thus not an objective feature of the world, but a subjective power; the mind's capacity to form inductive habits. The objectivity of causality, the objective support of inductive inference, is thus an illusion, an instance of what Hume calls the mind's “great propensity to spread itself on external objects” 

https://plato.stanford.edu/entries/induction-problem

It's true, reality is what remains when you stop believing. But why on earth do we think we're capable of stopping something as deeply embedded as belief when we can barely even notice the constant cacophony much closer to the surface?

The non-affirming negation

So is the solution to convince yourself of radical skepticism? No, for two reasons.

First, the layer of mind that is reinforcing your metaphysics is much deeper than the one you likely have access to when you try to consciously change your beliefs about the world. This results in a conflict between what you "know" (really, assume at a very deep level) and what you "believe." Obviously this will lead to painful cognitive dissonance.

Second, you don't actually have any more evidence for the past being unreal than you do for it being real. The certainty that it is unreal is just as delusional as the certainty that it is real. And yet it seems that those are the only two options: mustn't time be one or the other?

This is where we reach the non-affirming negation. An affirming negation is one that, while negating one thing, implicitly affirms another. "No, that's not true" generally implies that the thing is false. But it is possible to withdraw your belief in something without affirming something else. This is the non-affirming negation. You don't have to start believing in a crazy worldview to undo your belief in the default one. You can simply loosen your death grip on this worldview.

You may fear that letting go of those beliefs will make it harder to interact with the world in a sane way. But actually, folks like the Buddha are far more sane than the rest of us.

Taking existence for granted

So why is it worth releasing our metaphysical beliefs?

When you look around you right now, don't you feel something like "I've seen this all before (more or less)?" And don't you take it for granted that the next moment will offer something similar?

You're not paying attention to life because of the (completely unjustified, remember) assumption that you've experienced something very much like it before, and that you will continue to.

Yet there's actually something overwhelmingly glorious about existing at all. From time to time we may notice this, but our metaphysics typically swoops in and dampens it. No doubt it feels amazing to recognize something like "wow, we're made of star stuff," but concepts are always few steps removed from the primordial epiphany itself. You'll know you're getting closer when you're filled with gratitude, wonder, and awe beyond your wildest imagination. It's the most natural response to encountering the miracle of existence for the first time.