The time-lag argument for indirect perception

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Khethil
 
Reply Thu 22 Oct, 2009 02:08 pm
@kennethamy,
kennethamy;99236 wrote:
But see:

http://www.tcnj.edu/~lemorvan/APR_Proof.pdf

especially page 223 for an analysis and rebuttal of the time-lag argument.


Nice read and a fine argument. Interesting how the paper categorizes the different archetypes along the perceptional scale; it seems I'm most likely an indirect realist.
 
kennethamy
 
Reply Thu 22 Oct, 2009 03:06 pm
@Kielicious,
Kielicious;99294 wrote:
Yes I understand the implications of perceptions that are not instantaneous but I still dont see a problem with that. While it is true that the sun could have blown up and ceases to exist at this moment, and we wouldnt know for about 8 minutes, but we would still know 8 minutes later. Likewise, taking a picture of object X takes time to develop but why would we say that that picture isnt accurate of the object? It is accurate at that time. Sure object X could have changed dramatically during the development period but thats not what the picture is representing -its only representing the information that was received at that time. So while yes our perceptions lag a bit behind 'actual' reality but we would just end up finding out a tenth of a second later...

Am I interpreting this correctly or am I wayyy off the mark?


Yes. That seems to me right. So the time-lag argument does not show what Russell thought it showed.
 
Arjuna
 
Reply Thu 22 Oct, 2009 06:16 pm
@Kielicious,
Kielicious;99294 wrote:
Yes I understand the implications of perceptions that are not instantaneous but I still dont see a problem with that. While it is true that the sun could have blown up and ceases to exist at this moment, and we wouldnt know for about 8 minutes, but we would still know 8 minutes later. Likewise, taking a picture of object X takes time to develop but why would we say that that picture isnt accurate of the object? It is accurate at that time. Sure object X could have changed dramatically during the development period but thats not what the picture is representing -its only representing the information that was received at that time. So while yes our perceptions lag a bit behind 'actual' reality but we would just end up finding out a tenth of a second later...

Am I interpreting this correctly or am I wayyy off the mark?
I don't see any problem with the way you're interpreting it. All it is is an opportunity to notice the part Identity plays in knowledge.

Perceived data changes from one moment to the next. So why do we believe the star is the same object from one moment to the next? This belief obviously does not have its basis in sensory information. The star is an idea. We attach the ever changing sensory information to the unchanging identity.

It's possible to see this without the time lag issue. All the time lag issue does is cement the idea that everything is in flux... that we're seeing the world becoming. But as it becomes, we believe in contiguity past to future.

So as you draw a bottle of soda to your lips, you assume that the liquid will remain soda as it goes down your esophagus (and not change into gasoline.)

This assumption is not empirically based. We know it, but this knowledge can't be based on observation, because we can't observe the future. We'll say it's based in Reason. Although we can't find a good logical argument supporting the assumption, although minds as great as Hume's tried.

None of this is any assault on anybody's right to operate according to whatever scheme they see fit. As far as I can see, "so what?" is the proper practical response. The answer to "so what?" is part of philosophy.

Can you really found your knowledge on observation alone? Or does knowledge inevitably require Reason to exist at all.

Reason is always there... operating on sensory information. The sensory information doesn't come first. It doesn't create knowledge.

Reason creates knowledge. Believe it or don't. And the story of philosophy goes on from here. Smile
 
derrickfarnell
 
Reply Sun 25 Oct, 2009 09:47 am
@Khethil,
Thanks for your interesting thoughts everyone! I've just got back from a break.

It's interesting that while the conclusion is the accepted view of perception (no pun intended) in psychology, in philosophy it is currently a minority view.
 
kennethamy
 
Reply Sun 25 Oct, 2009 01:45 pm
@derrickfarnell,
derrick.farnell;99727 wrote:
Thanks for your interesting thoughts everyone! I've just got back from a break.

It's interesting that while the conclusion is the accepted view of perception (no pun intended) in psychology, in philosophy it is currently a minority view.


Yes, it often happens that scientists believe that scientific findings have philosophical implications they really do not have. Free will is still another example. Scientists should stick to what they know about.
 
pagan
 
Reply Sun 8 Nov, 2009 02:02 pm
@kennethamy,
The time lag observation is important, because it raises the question from the objective point of view "when and where is now?" eg where and when is 'now' for the star sirius?

We assume it exists but this is a strange assumption in conjunction with objectivity. Firstly objectivity is necessarily not a now type observation. Objective observation requires experiment and that is necessarily not now. It requires rational analysis. It also requires textual language. Science is the developement of the ultimate fixed text. A textual model of the world is post now. It is attempting to be timeless (else it isn't universal truth in time, and universality is essential for the scientific text to develope). It is also spatially independent too of course. ie the truth of the text is not dependant upon where and when it is developed or read.

But why do we believe that the 'now' of sirius exists? ..... because we believe from subjective experience that the 'now' exists. That is not scientific evidence (as it stands in the present form of science). Yet science still tends to believe in it.

But the contradiction is that we recognise that we do not experience the 'now' of sirius when we see it ....... due to scientific information. So objectively we say we experience our own perceptual 'now' instead!

There is a circular contradiction going on here.
 
pagan
 
Reply Mon 9 Nov, 2009 08:33 am
@pagan,
Quote:
Pierre Le Morvan............. in the vast majority of cases of perception (where we are dealing with relatively nearby physical objects or events), perception occurs so quickly that it seems to occur instantaneously. This may explain much of the intuitive pull of the idea that we cannot now be aware of something (e.g., a distant star) that no longer exists, because in the vast majority of our day-to-day perceptions we deal with relatively nearby objects or events which continue to exist. Hence, it may strike us as odd to think that we can now be aware of something that no longer exists. But when we realize that all perception (at least in the actual world and physically similar possible worlds) involves some time lag (however minute it may be in most cases), and realize the vast extent of the temporal and spatial distances involved in perceiving celestial bodies, the idea that we could now be aware of a celestial body which no longer exists comes to seem less odd. It's important to keep in mind here that Direct Realists need not be committed to the claim that we can now be aware of the no-longer existent object as it is now, but only that we can now be aware of the once-existent object as it used to be.
what is interesting here is the different relationship to existence. ie direct realism is posited here as the perception (awareness) of something that no longer exists. The reason that such an argument is possible is because 'existence' is still assumed to be necessarily and directly connected to a sense of universal 'now'. ie the 'now' is existence and existence is the 'now'. Awareness and perception are also presumably considered in the 'now' and as such are considered to exist. Therefore via Le Morvan it follows from the scientific knowledge of light that 'now' existing awareness can be 'of' no-longer existent objects.

For me this is so convoluted around the concepts of now, existence, and direct awareness that i wonder what use it is? Further it does not challenge the assumption that the 'now' exists nor does it challenge the idea that something can only exist in the 'now'.

I would have thought a better argument for direct realists to adopt was a redefining of existence such that existence is not uniquely constrained to the 'now'. In doing so it follows that the 'now' no longer holds a primary and fundamental link to reality. Further ..... if the 'now' is not directly tied to existence (and vice versa) then it brings into question its existence. As such the entire time lag objection to direct perception would fall apart and the objectivity scientific knowledge would not presume the 'now' exists on the basis of subjective experience.

..... in other words 'now' becomes to some extent a perceptual illusion. This may sound like another objection to direct realism, but in fact it is not because as Le Morvan points out there is a difference between naive realism and direct realism generally. eg. direct realism can accomodate the 'now' as an illusion while maintaining that perception generally is direct. The problems arise with regard to the time lag argument if a direct realist believes that we directly percieve the 'now'.

However ..... if the 'now' does not exist there are great philosophical and scientific consequences.
 
 

 
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