Wednesday, May 29, 2013

1% Skepticism

I find myself, right now, 99% confident that I am who I think I am, living in a broad world of the kind I think I live in. The remaining 1% of my credence I reserve for all radically skeptical scenarios combined.

Most of us, I think, don't reserve even 1% of our credence for radically skeptical scenarios. Maybe if you're philosophically inclined and not entirely hostile to skepticism, you'd be willing to say, in certain reflective moments, that there is some chance, maybe about 1%, that some radically skeptical scenario obtains. But such acknowledgements are typically not truly felt and lived -- not in any durable way. Skeptical doubts stay in the classroom, in the office, in the books. They don't come home with you.

What if skeptical doubt did come home with you? What would it be like really to live with 1% of your credence distributed among radically skeptical scenarios?

It depends in part on what the scenarios are. Let mention three that I have trouble entirely dispelling.

Random origins skepticism. Most physicists think that there is a finite though tiny chance that a brain or brain and body could randomly congeal from disorganized matter. In a sufficiently large and diverse universe, we should expect this chance sometimes to be realized. A question that then arises is: Are randomly congealed beings relatively more or less common than beings arising from what we think of as the ordinary process of billions of years of biological evolution? A difficult cosmological question! I see room for some doubt about the matter, so it seems I ought to reserve some subjective credence for the possibility that such freak-chance beings are common enough that I might be one of them, and thus that I lack the sort of past, and probably future, that I think I have. (This is the Boltzmann brain hypothesis.)

Simulation skepticism. If it is possible to create consciousness artificially inside computers, then likely it is also possible to create conscious beings with radically false autobiographical memories and radically false impressions about the sort of world they live in. I don't feel I can entirely exclude the possibility that I am such a radically mistaken artificial being -- for example a being limited to a few hours' existence in a 22nd-century child's computer game. (This is a skeptical version of the "simulation" possibility, discussed non-skeptically by Nick Bostrom here and by David Chalmers here.)

Dream skepticism. Zhuangzi dreamed he was a butterfly. After he woke he wasn't sure if he was Zhuangzi who had dreamed he was a butterfly or a butterfly dreaming he was Zhuangzi. I'm inclined to think the phenomenology of dreaming is very different from the phenomenology of waking, and thus that my current experiences are excellent grounds for thinking I am indeed awake. But I am not absolutely sure of that. And if I might be dreaming, then I might not really have the family and career and past life I think I do.

I don't believe that any such skeptical scenario is true, or even very likely. On reflection, I am inclined to grant all such skeptical scenarios combined about 1% of my credence. In a way, that's not much. But in another way, that's quite a bit.

Suppose someone came to me with two ten-sided dice and said this: I will roll these two dice, and if they both come up "1", you will die. Would I rest in gentle confidence that a 99% chance of living is quite an excellent chance? Or suppose I were to learn that seven unnamed students from my daughter's largish elementary school had just been abducted into irrecoverable slavery. Would I feel sorry for those students but feel no real concern about my daughter, since the odds are so good she is not among them?

I sit on by back patio. If some radically skeptical scenario is true, then my daughter does not exist, or I will be dead within a minute as the disorganized soup from which I've congealed consumes me again, or my life will end in an hour when the child grows bored with the game in which I am instantiated. Should I be unconcerned about these possibilities because I judge it to be 99% likely that nothing of this sort is so?

I hear a voice from inside the house. It's my wife. How would it change things if instead of taking it for granted that she exists, I held it to be 99% likely that she exists? -- or 99.5% likely, if I allow a 50% chance of her real existence given a skeptical scenario?

Often, I visually imagine negative events that have a small chance of occurring. This morning, the newspaper told me of five teenagers who died in a street race; I looked at my own teenage son, who was readying for school, imagining his death. Or I'm passenger in an airplane descending through heavy fog and turbulence, and I imagine a crash. I hear of a streak of identity thefts in Riverside, see that someone has messed with our mailbox, and imagine our bank accounts drained. If I am a 1% skeptic, shall I then also imagine the world's suddenly splitting into void, Godzilla's rising over the horizon for the child's entertainment, my suddenly floating off into the air, opening my front door to find no ordinary suburban street but rather Wonderland or darkness?

I have, in fact, started to imagine these things more often. I don't believe them -- no more than I believe the plane will crash. Given non-skepticism, the plane is much less than 1% likely to crash. If I am a 1% skeptic, then I should probably think it more likely that am I Boltzmann brain or a short-lived artificial consciousness or a much-deceived dreamer, than that the plane will crash. Would it be more rational, then, for me to dwell on those possibilities than on the possible plane crash?

I am undecided about doing some chore. I could weed the yard. Or I could sip tea, enjoy the shade, and read Borges. I teeter right on the cusp about which is the wiser choice. But skepticism has not yet crossed my mind. Once it does, the scale is tipped. The 1% chance that the weeds are an illusion or a mere temporary thing -- the small but non-trivial possibility that this moment here is all I have before I die or the world collapses around me or I wake to something entirely new -- favors Borges.

If my credence in the durable reality of this patio and this book were to fall much below 99% -- if my credence were to fall, say, to only 80% or 50%, I would be laid low. My death might well be upon me within minutes. I would seek my family, my seeming-family; at the same time, my doubts would isolate me from them. I could not, I think, feel full proper intimacy while I regard my partner in intimacy as fairly likely to be mere froth or illusion. Even if my wife and children are not froth and illusion, such large doubt is disaster, for it would derange my choices and emotions, and few people would understand my doubts, even if my own careful reflection revealed those doubts to be well-grounded. Everyone around would see me only as insane with foolish philosophy.

1% skepticism does not have this effect though. I can still enjoy my Borges, even flatter myself somewhat with my excellent excuse for avoiding the weeds, which I am of course in fact almost certain do exist.

[For related reflections see Waterfall Skepticism.]

Monday, May 27, 2013

Joshua Afire in Canaan

Today is Memorial Day in the U.S. I have written a story about war, two pages from the perspective of Joshua from the Old Testament -- a celebration of violence and genocide, in Joshua's hard, sure voice. I hope it's unnecessary to add that Joshua's perspective is not my own.

Story here.

Wednesday, May 22, 2013

Developments at the Brains Blog

Readers of the Splintered Mind might be interested in this news about developments at the Brains blog, including regular symposia on articles from the journal Mind & Language, a new series of podcasts by Adam Shriver, and a stint as Brains Featured Scholar by former Splintered Mind guest blogger Lisa Bortolotti.

Sounds fun to me!

Is Crazyism Obvious?

"Crazyism" about the metaphysics of mind, as I define it, is the view that something bizarre and undeserving of credence must be among the core truths about the mind. In my central article on the topic, I develop the view by defending two subordinate theses: universal bizarreness and universal dubiety.

Univeral bizarreness is the view that well-developed metaphysical approaches to the mind will inevitably conflict sharply with common sense. My defense of universal bizarreness turns on the failure of any contemporary or historical philosopher to develop a thoroughly commonsensical metaphysics of mind. That empirical fact about the history of philosophy is best explained, I think, by the incoherence of common sense in matters of mental metaphysics. If commonsense is incoherent, no broad-reaching coherent metaphysical system could respect it all.

Universal dubiety is the view that all of the broad approaches to the metaphysics of mind -- materialism, dualism, idealism, or some rejection or compromise alternative -- are dubious, none warranting credence much above 50%. My defense of universal dubiety turns on the apparent inability of any combination of empirical scientific, abstract theoretical, or commonsensical methods, in anything like their current state, to resolve fundamental metaphysical questions of this sort.

The most common objection I hear to crazyism is that it's obvious. I am somewhat puzzled by this objection!

Is it obvious that all coherent, well-developed approaches to the metaphysics of mind conflict with common sense? Perhaps that was Kant’s view, especially in the antimonies, but Kant’s view of the antimonies is not universally accepted. Scientifically oriented materialists often reject common sense, but doing so is entirely consistent with thinking that there might be a commonsensical way of to develop dualism. Also, it remains common argumentative practice in the metaphysics of mind to highlight sharp violations of common sense in views one opposes – idealism, panpsychism, Chinese-nation functionalism, eliminative materialism – as though the bizarreness of those views were a powerful consideration against them. This practice seems problematic if it is generally agreed that all well-developed metaphysical theories sharply violate common sense.

Is it obvious that no existing combination of methods could, within the next several decades – within our active philosophical lifetimes – appropriately push us to a warranted belief (or credence much above 50%) in materialism or whatever option might usurp materialism’s current popularity in the philosophical community? This doesn’t seem to be the attitude of most of my materialist friends. Indeed, even other skeptics about our ability to solve the mind-body problem, such as Colin McGinn and Noam Chomsky, seem to assume a broadly naturalistic, scientific perspective toward the world, excluding from outset such options as idealism and substance dualism.

Finally, it's odd that the supposed obviousness of crazyism is offered as an objection to my work on the topic. Even if the view I am espousing is just boringly obvious to well-informed philosophers, it might still be worth gathering and presenting the considerations in favor of it, if (as I believe), it hasn't properly been done before. But I am eagerly open to reading suggestions on this last point!

Friday, May 17, 2013


Driving her son to school, she saw the perfect tree. The perfect tree stood small and twisted upon the center divider. It commanded its cousins, suburbanly spaced along the same divider. It commanded the giant eucalyptuses that lined the old road. It was centerpoint of a universe of weeds and flowers, cars and houses, birds, beetles, clouds, dust, stone, gutters, children, and crumpled paper. She drove over the small lip of the road onto the sidewalk and the dead leaves, parking. Her son asked was something wrong? She opened her door, walked across onto the median, and sat in the dirt, facing the tree.

Her son followed but did not understand. After a while, he walked toward school.

That afternoon, the phone rang in her car. That afternoon, she received a parking ticket. That evening, her husband came and sat with her beneath the tree. He said some words that seemed like gentle pleading. He left, he came back, he fell asleep at her feet while she sat.

Dawn speared through the eucalyptus, painting patches on the perfect tree. The perfect tree had a thousand red elbows. The perfect tree offered the world its berries, its light, its air, its scent of apple, of dust, chocolate, rubber, marjoram, closet floors. Its leaves were a chaos on which it would be impossible to improve. She breathed the oxygen of its photosynthesis. She drew a finger across a branch, leaving an invisible trace of her skin’s oil. Her husband brought breakfast, cancelled her classes, defended her rights against the police. A friend drove her car away.

.... [For the full-length and updated version, please email me.

Wednesday, May 15, 2013

What Are You Noticing When You Adjust Your Binoculars?

Maja Spener has written an interesting critique of my 2011 book, Perplexities of Consciousness, for a forthcoming book symposium at Philosophical Studies. My book is an extended argument that people have very poor knowledge of their own conscious experience, even of what one might have thought would be fairly obvious-seeming features of their currently ongoing experience (such as whether it is sparse or full of abundant detail, whether it is visually doubled, whether they have pervasive auditory experience of the silent surfaces around them). Maja argues that we have good introspective knowledge in at least one class of cases: cases in which our skillful negotiation with the world depends on what she calls "introspection-reliant abilities".

Maja provides examples of two such introspection-reliant abilities: choosing the right amount of food to order at a restaurant (which relies on knowledge of how hungry you feel) and adjusting binoculars (which relies on knowing how blurry the target objects look).

Let's consider, then, Maja's binoculars. What, exactly, are you noticing when you adjust your binoculars?

Consider other cases of optical reflection and refraction. I see an oar half-submerged in water. In some sense, maybe, it "looks bent". Is this a judgment about my visual experience of the oar or instead a judgment about the optical structure of my environment? -- or a bit of both? How about when I view myself in the bathroom mirror? Normally during my morning routine, I seem to be reaching judgments primarily about my body and secondarily about the mirror, and hardly at all about my visual experience. (At least, not unless we accept some kind of introspective foundationalism on which all judgments about the outside world are grounded on prior judgments about experience.) Or suppose I'm just out of the shower and the mirror is foggy; in this case my primary judgment seems to concern neither my body nor my visual experience but rather the state of the mirror. Similarly, perhaps, if the mirror is warped -- or if I am looking through a warped window, or a fisheye lens, or using a maladjusted review mirror at night, or looking in a carnival mirror.

If I can reach such judgments directly without antecedent judgments about my visual experience, perhaps analogously in the binoculars case? Or is there maybe instead some interaction among phenomenal judgments about experience and optical or objectual judgments, or some indeterminacy about what sort of judgment it really is? We can create, I'm inclined to think, a garden path between the normal bathroom mirror case (seemingly not an introspective judgment about visual experience) and the blurry binoculars case (seemingly an introspective judgment about visual experience), going either direction, and thus into self-contradiction. (For related cases feeding related worries see my essay in draft The Problem of Known Illusion and the Resemblance of Experience to Reality.)

Another avenue of resistance to the binoculars case might be this. Suppose I'm looking at a picture on a rather dodgy computer monitor and it looks too blue, so I blame the monitor and change the settings. Arguably, I could have done this without introspection: I reach a normal, non-introspective visual judgment that the picture of the baby seal is tinted blue. But I know that baby seals are white. So I blame the monitor and adjust. Or maybe I have a real baby seal in a room with dubious, theatrical lighting. I reach a normal visual assessment of the seal as tinted blue, so I know the lighting much be off and I ask the lighting techs to adjust. Similarly perhaps, then, if I gaze at a real baby seal through blurry binoculars: I reach a normal, non-introspective judgment of the baby seal as blurry-edged. But I know that baby seals have sharp edges. So I blame the binoculars and adjust. Need this be introspective at all, need it concern visual experience at all?

In the same way, maybe, I see spears of light spiking out of streetlamps at night -- an illusion, some imperfection of my eyes or eyewear. When I know I am being betrayed by optics, am I necessarily introspecting, or might I just be correcting my normal non-introspective visual assessments?

This is a nest of issues I am struggling with, making less progress than I would like. Maybe Maja is right, then. But if so, it will take further work to show.

Wednesday, May 08, 2013


Through a harmony of dendrites, Sarah came to feel touch upon Abraham’s skin. They were waltzing upon the beach, Ishbak on the immutable piano, and a frond brushed Abraham’s back. Sarah felt the frond as though on her own back. She caressed Abraham’s left shoulder and felt the caress as though upon her own shoulder. Abraham’s right hand was touching the skin under Sarah’s arm, and Sarah felt not only his fingers there in the usual way, but also a new complement: the smoothness of her ribs upon her own right hand. She had been feeling that smoothness for a while, she realized, intermingled with the more familiar touch of Abraham’s left hand upon her right as they danced.

They danced three songs in this manner, then lay together upon the sand. Sarah touched the back of her neck with a twig and saw Abraham scratch his own neck. They made love in a new way.

Sarah gazed upon Abraham as he observed the sky. She called to Ishbak and Midian. Sarah and Abraham lay face down upon blankets while the sons of Keturah touched their backs, and Sarah learned to distinguish Abraham’s sensations from her own. She now had two backs, two bodies.

Through a harmony of retinas, Sarah came to see through Abraham’s eyes. At first, it was a faint tint upon her field of view – her own form, maybe, bent toward the fire pit, as Abraham watched her from the side, her figure like a wraith upon the fire that she more vividly saw. The wraith was jumpy, unpredictable; she could not fully guess Abraham’s saccades as his eyes gathered the scene. Over days, the visions livened and settled. Sarah did not know if she merely learned better to anticipate Abraham’s eye movements or if she instead also gained partial control.

[for the second half of this story, email me at eschwitz at domain:]

Monday, May 06, 2013

Two Types of Hallucination

Oliver Sacks is one of the great essayists of our time. I have just finished his book Hallucinations.

Sacks does not, I think, adequately distinguish two types of hallucination. I will call them doxastic and phenomenal. In a phenomenal hallucination of A, one has sensory experience as of A. In a doxastic hallucination, one thinks one has sensory experience as of A. The two can come apart.

Consider this description, from page 99 of Hallucinations (and attributed to Daniel Breslaw via David Ebin's book The Drug Experience).

The heavens above me, a night sky spangled with eyes of flame, dissolve into the most overpowering array of colors I have ever seen or imagined; many of the colors are entirely new -- areas of the spectrum which I seem to have hitherto overlooked. The colors do not stand still, but move and flow in every direction; my field of vision is a mosaic of unbelievable complexity. To reproduce an instant of it would involve years of labor, that is, if one were able to reproduce colors of equivalent brilliance and intensity.
Here are two ways in which you might come to believe the above about your experience: (1.) You might actually have visual experiences of the sort described, including of colors entirely new and previously unimagined and of a complexity that would require years of labor to describe. Or (2.) you might shortcut all that and simply arrive straightaway at the belief that you are undergoing or have undergone such an experience -- perhaps with the aid of some unusual visual experiences, but not really of the novelty and complexity described. If the former, you have phenomenally hallucinated wholly novel colors. If the latter, you have merely doxastically hallucinated them.

The difference seems important -- crucial even, if we are going to understand the boundaries of experience as revealed by hallucination. And yet phenomenal vs. merely doxastic hallucinations might be hard to distinguish on the basis of verbal report alone, and almost by definition subjects will be apt to confuse the two. I can recall no point in the book where Sacks displays sensitivity to this issue.

Once I was attuned to it, the issue nagged at me again and again in reading:

Time was immensely distended. The elevator descended, "passing a floor every hundred years" (p. 100).

Then my whole life flashed in my mind from birth to the present, with every detail that ever happened, every feeling and thought, visual and emotional was there in an instant (p. 102).

I have had musical hallucinations (when taking chloral hydrate as a sleeping aid) which were continuations of dream music into the waking state -- once with a Mozart quintet. My normal musical memory and imagery is not that strong -- I am quite incapable of hearing every instrument in a quintet, let alone an orchestra -- so the experience of hearing the Mozart, hearing every instrument, was a startling (and beautiful) one (p. 213).

The possibility of merely doxastic hallucination might arise especially acutely when subjects report highly unusual, almost inconceivable, experiences or incredible detail beyond normal perception and imagery; but of course the possibility is present in more mundane hallucination reports too.

(A fan of Dennett might suggest that there's no difference between the phenomenal and doxastic hallucinations; but I don't know what Dennett himself would say -- probably something more complex than that.)

Wednesday, May 01, 2013

The Tyrant's Headache

When the doctors couldn’t cure the Tyrant’s headache, he called upon the philosophers. “Show me some necessary condition for having a headache, which I can defeat!”

The philosophers sent forth the great David K. Lewis in magician’s robes....

[See the remainder of this story here. Hint: It doesn't have a happy ending.]