Tuesday, November 4, 2014

From Experience to Metaphysics: A Summary

This post is a summary of "From Experience to Metaphysics" by Jiri Benovsky.

Check it. We'z about to go to da deps of filosofy: metaphysics. Metaphysics be about da fundamental nature of reality. It's not that new-age crap about pyramids with eyes you see in book stores. It's even deeper!!!!1!!!!11!1!!(I know, what could possibly be more profound than "everything happens for a reason"?)

The Argument in a Nutshell
(A) Our metaphysical theories about the world are grounded in intuitions that we get from the particular way we happen to perceive the world.  But the way we perceive the world is contingent on our brains' perceptual architecture. The architecture could have been otherwise and thus could have caused us to perceive the world differently and in ways that favor different metaphysical theories. 
(B) Also, the way we perceive the world is compatible with mutually exclusive metaphysical theories. 
(C) Given (A) and (B), we should avoid appealing to intuitions based in perception to support metaphysical theories.

I'll illustrate the main argument instead of explaining it. It'll make it easier to understand.

Case 1
You perceive an apple on a table.  You say "look, there's an apple and a table over there." Bob looks where you are looking and says "Oh, I see them, and I also see a tapple." "What's a tapple?" you ask. Bob be like, "a tapple is an object made up of the top of an apple and the left-side of a table." Then you be like, "dafuk you talking 'bout? There ain't no tapples, just apples and tables." Bob be like "no, dude! It's right there! You're looking right at it!"  

You walk over and touch the table and apple and you be like, "dawg, this is a table and this is an apple. I can touch them, see them, taste them, and smell them. Ain't no tapples up in herr." Bob walks over and touches to top of the apple and the left side of the table and he be like "dawg, this is a tapple. I can touch it, see it, smell it, taste it. It's real, dawg."

Why do we say tables and chairs exist but tapples don't? The problem is that our perceptions support both claims about what exists. Our perceptions are consistent with both the existence of only apples and tables and with the existence of tapples too. You could argue against Bob that, "no, we perceive tables and chairs in a way that's different from the way we perceive tapples.  But Bob could--to quote Missy Elliot--flip it and reverse it and give you the exact argument for the existence of tapples. That is, he could say "yes, you're right. We do perceive tapples differently from tables and chairs, that's why tapples exist and tables and chairs don't." Ah, snap! 

To summarize, if only tapples existed our perceptual experience would be the same as if only apples and tables existed. It would also be the same if all three objects existed. Our visual experience of the world can't tell us the "right way" to chop it up into objects.  Our perception of the world will always be consistent with an infinite number of ways of dividing phenomenal experience into entities and parts.  Because of this fact, Benovsky argues that when we do metaphysics we shouldn't appeal to intuitions grounded in how we perceive the world.

Case 2
Lets look at one more example. Perceiving a table and an apple, you be like "check out that table and apple." Bob be like, "I don't see no table or apple, alz I see is fundamental particles arranged tablewise and applewise."  You be like "Dawg, I can freaking sit on the table and eat the apple. Tables and chairs exist. There's a freakin' table and an apple over there." Bob be like "Dude, you ain't sittin' on no 'table'. You be sittin' on a collection of fundamental particles arranged in a table shape. Tables don't exist, only fundamental particles do. They can vary their arrangements into table shapes or apple shapes." (Bob started talking fancy-talk) 

Again, we see that two competing metaphysical theories about the fundamental units of existence (macro objects vs fundamental particles) are compatible with the same perception. Both theories will yield exactly the same observations. If only fundamental particles exist and can be arranged tablewise and applewise, our experience of the world will be exactly the same as though tables and apples are real objects too. For this reason, Benovsky argues that metaphysical arguments shouldn't rest on intuitions derived from how we perceive the world.

Case 3
Let's do one last example because this is the most interesting case.

As you and Bob argue, over the course of the next few months, the apple slowly changes from a crunchy, red, shiny object to a brown rotten object. On day 67 you be like "Dawg, that rotten apple tho." Bob be like "oh, you mean the apple that used to be crunchy, red, and shiny?" You be like, "No, that ain't the same apple. The apple from 67 days ago was crunchy, red, and shiny. This one be brown and rotten. It ain't the same apple."  Bob be like, "Dawg, that's what happens when apples get old. They turn brown and rot. It's the same apple." You be like "Dude, no it ain't the same apple. How can two things be the same if they don't have the same properties? Same means no differences. There are differences between the apple from 67 days ago and this one. In fact, there's nothing the same about them. They ain't the same apple."  Bob be like, "Dawg, why you tripping? You saw it change gradually er' day. It's the same apple." You be like, "Dude, no. I saw lots of different apples, each one very similar to the one I saw before it. They were all different apples."

Again, we notice that both metaphysical theories equally conform with our observations. There could be some entity whose properties change over time or sequences of similar objects that disappear and are replaced at a rate too fast for us to notice. It's true that the common sense view is that objects persist over time but if a string of object replacements happened at a fast enough rate, we'd perceive exactly the same thing as the latter.  After all, that's how movies work: strings of new images passing before us at a rate of 24 frames per second create the illusion of a single object's continuity over time. That single apple you see "rotting" on the screen is in fact a series of distinct images of apples, all of which are slightly different from the previous one.  

Our bias towards endurantism (the theory that objects persist over time) results from how we (contingently) experience the world. Just because we favor one way of interpreting our perceptions doesn't mean this is actually how the world is. Our perceptual system could have worked differently giving us different experiences of the world...

Let's look at the cognitive science to see why we shouldn't put too much stock in metaphysical intuitions grounded in our perception of the world. Benovsky says we should be skeptical of perception-based reasons for endurantism because the way we experience the world is (i) contingent (our brain could have been configured differently resulting in different types of perceptions) (ii) fully compatible with the world being perdurantist (movement/change results from the successive emergence and disappearance of similar objects). If this sounds loco, welcome to philosophy.

Cog. Sci Data: Humans Attribute Spacio-Temporal Continuity Even When It Isn't There
Click on the link: http://ruccs.rutgers.edu/val/images/demos/motoccocclusionextended.mov
When the experiment starts 4 dots will blink. You have to track them for the duration of the (short) experiment. Do not read further until you do the experiment.
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Notice that when the dots go behind the bars you track them as though the object coming out is the same one that went in. But the dot that goes behind the occlusion isn't the same as the one coming out. Each moving dot is not one dot but a series of dots appearing and disappearing in succession across the screen which give the illusion of a single dot moving across your screen that persists over time. Our brain attributes spacio-temporal continuity to the series of distinct dots. 

Again, this is how movies work. Imagine watching a movie of a ball crossing the screen. There ain't no one ball that persists over time. There are a series of distinct ball images being projected at 24 frames/second which gives the illusion of a single ball traveling across the screen. Ain't no ball.  Nope.  Your mind created it.  

And here's the crazy part. You can even know that your brain is creating the illusion of a single persisting ball going across the screen but you still won't be able to shake the illusion. You aren't able to see the 24 distinct ball images/second.  Our brain constructs an image then we perceive what our brain constructs. We don't perceive "raw" reality.  Our brain has a bias towards attributing spacio-temporal unity to series of like objects coming in and out of existence.  We can't make the distinction even if we wanted to.

But wait! There's more! If a series of objects are coming in and out of existence across a screen at the right speeds, when they temporarily go behind a bar and come out in the same trajectory, we'll attribute spacio-temporal unity even if their shape and color get changed on the exit.  For example, a series of squares rapidly come in and out of existence across the screen giving the illusion of a single square moving across the screen. When that square goes behind a bar and comes out with a different shape and color, we still think of it as the same object so long as it follows the trajectory of the previous sequence of squares. Our brain causes spacio-temporal continuity to trump property change! But how is the new object the same object as the square if it isn't a square anymore? Saying the red crunchy apple and the brown rotten apple are two different objects isn't sounding so crazy after all...

The Bottom Line
Our perceptions are consistent with competing metaphysical theories. We can be biased toward one theory based on the contingent way human brains happen to work.  Our brains force one interpretation on the raw data that is sometimes inconsistent with the way we know it to actually be.  However, even when we know that something isn't as we perceive it, we still can't help but perceive it a certain way. Even if you wanted to perceive a movie as a series of still frames, you couldn't do it because of your brain architecture. Your brain processes the data and constructs an image that you perceive. What you perceive isn't "raw" reality but an interpretation that your brain constructs. 

Some cool TED talks on how our brain constructs reality: http://www.ted.com/talks/beau_lotto_optical_illusions_show_how_we_see
http://www.ted.com/talks/al_seckel_says_our_brains_are_mis_wired















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