How do we know there is a behind us?

Darkneos September 19, 2022 at 22:30 7475 views 36 comments
https://www.quora.com/How-do-i-know-that-solipsism-is-false/answer/Gerard-Cec?ch=10&oid=22123926&share=593e9803&srid=uHpSfZ&target_type=answer

Just this answer. I mean I know memory is a thing but just because you can't see something doesn't mean it stops existing when you look away, and failing to remember where stuff is can bit you. Also a mirror isn't an illusion since it reflects what's behind you, otherwise rearviews would be worthelss.

Comments (36)

Paine September 19, 2022 at 22:50 #740994
The idea is undercut because it uses the means of verification that are being denied in order to promote the proposition.

Tate September 19, 2022 at 22:55 #740995
Reply to Darkneos
You've demonstrated that it's possible to doubt it. That shows that the knowledge most be a posteriori. Yet, if you haven't seen it, what experience do you base the knowledge on?

javi2541997 September 20, 2022 at 04:05 #741057
Quoting Tate
Yet, if you haven't seen it, what experience do you base the knowledge on?


:up: :100:
Agent Smith September 20, 2022 at 05:12 #741067
The question reminds me of predator-prey eye positions. Prey have eyes on the sides of their head, giving them a 360[sup]o[/sup] field of vision in order to detect approaching predators. Predators, on the other hand, have front-facing eyes for stereoscopic/binocular vision so that they can judge distance accurately during a hunt. Predators can't see behind; prey can and still they get caught. Oh bummer!

Cuthbert September 20, 2022 at 10:44 #741135
IQuoting Tate
You've demonstrated that it's possible to doubt it.


Is it possible coherently to doubt it? If it's true, all statements about the past are false. In that case, I didn't write the last sentence. I did not believe that I was writing it. I have not read the OP or looked at the quora link. There was no link.
Agent Smith September 20, 2022 at 11:49 #741147
[quote=Darkneos]How do we know there is a behind us?[/quote]

The problem, mon ami, is we don't even know if there's a front us!

:cool:
Tate September 20, 2022 at 12:07 #741150
Quoting Cuthbert
Is it possible coherently to doubt it?


I don't think it's possible to doubt that there is space behind me. I apparently know that there is space a priori.

But as for objects occupying that space, I can imagine that a void follows me around, so I can doubt the objects. That means if I have knowledge of them, it's a posteriori.

Quoting Cuthbert
If it's true, all statements about the past are false.


Could you explain why?

Cuthbert September 20, 2022 at 12:18 #741152
Quoting Tate
Could you explain why


Alas, no, because I misread the whole thing. I thought it was about whether we can doubt that any time exists except the present.

I suppose if there is no world out there (the doubt is coherent and the hypothesis happens to be true), but there is a past and there are other people, then it becomes testable. I could ask my friend, who was on the other side of the door, whether the world continued to exist while I had the door closed. Do that a few times in different circumstances and I might begin to wonder whether my being on my side of the door is wholly irrelevant to the question of what is on the other side of it. It sounds like a project for a baby of 4 - 6 months, when we are getting used to the idea that teddy hiding is still teddy.
Tate September 20, 2022 at 12:22 #741153
Quoting Cuthbert
I suppose if there is no world out there (the doubt is coherent and the hypothesis happens to be true),


The question isn't about whether there's a world. It's about whether there's anything behind you.
Cuthbert September 20, 2022 at 15:10 #741188
@Tate Yes, I got that. After a slow start. My answer is to ask a friend to look and check for me. The world and other people exist - it's just 'behind' that's the problem - so the question can be settled.
Tate September 20, 2022 at 17:03 #741208
Quoting Cuthbert
Yes, I got that. After a slow start. My answer is to ask a friend to look and check for me.


You can't do that continuously though.

As I mentioned, the knowledge that there is space behind you is probably a priori because you can't doubt it. If you tried to imagine no space, that would conflict with the idea of 'behind '

So you know there is space a priori. How do you know there are predictable objects behind you? I think that's part of a dynamic model that's coming from you. In other words, it's a hypothesis. You don't know what's behind you until you do ask a friend, or turn around.
Darkneos September 20, 2022 at 22:39 #741258
Reply to Tate How do you know? You just do. Let's also not forget that there are dire consequences for doubting a behind you. Try breaking hard in traffic and see the legitimacy of such a doubt.

Reply to Agent Smith Pretty sure we do.
Fooloso4 September 20, 2022 at 22:44 #741260
Reply to Darkneos

The only sensible answer is to keep turning around, faster and faster, until you puke.
Agent Smith September 20, 2022 at 22:54 #741264
Quoting Darkneos
Pretty sure we do.


Deus deceptor? The whole thing could be a one giant illusion (maya). Magick! The question of front and behind or on the sides is moot.
Tate September 20, 2022 at 23:39 #741276
Quoting Darkneos
How do you know? You just do


Sure. You know there's "stuff" behind you. That's a model.
Darkneos September 21, 2022 at 00:12 #741288
Reply to Agent Smith I don't consider that possibility valid.

Reply to Tate More like reality, no amount of philosophical musing will change that.
Agent Smith September 21, 2022 at 00:16 #741291
Quoting Darkneos
I don't consider that possibility valid


It is only an extension of your "behind us" idea which is basically a reserved skeptical argument; I just went the whole nine yards mon ami and let the seed you planted bloom in full glory.
Tate September 21, 2022 at 00:28 #741295
Quoting Darkneos
More like reality, no amount of philosophical musing will change that.


Especially if you don't do any philosophical musing.

Darkneos September 21, 2022 at 00:41 #741303
Reply to Agent Smith There is no seed, it's a non starter and not to mention not even related to the behind you question.

Reply to Tate Whether you do or don't it won't change that there is something behind you. Though it does say something how philosophical musings don't change reality, sometimes it makes me question why even bother asking such questions.
Agent Smith September 21, 2022 at 00:44 #741305
Quoting Darkneos
There is no seed, it's a non starter and not to mention not even related to the behind you question


Ok!
Tate September 21, 2022 at 00:56 #741310
Quoting Darkneos
sometimes it makes me question why even bother asking such questions.


Well, there you have it.
Cuthbert September 21, 2022 at 11:36 #741446
Quoting Tate
You don't know what's behind you until you do ask a friend, or turn around.


I wouldn't say that's always true. As I write, my kitchen is behind me. You did not know that - but I did. That's a difference of the states of knowledge betwen us. If we deny knowledge to both of us - to you, because you have no idea where my kitchen is, and to me, because it's behind me - then I'm not sure how to express the clear difference between us in respect of knowledge. It seems as if there was a clear difference and now a theory has been introduced to smudge it or invalidate it. My first instinct is to doubt the theory and to preserve the phenomena - the phenomena in this case being that I do know which room is behind me, even without turning round, and most other people don't know.

What theory is causing the problem? Perhaps it's something like this: "If it's possible to doubt something, then the knowledge of that thing must be a posteriori [dependent on experience]." We now have a counter-example. It's possible for me to doubt that my kitchen is behind me. I can't see it. And still I have knowledge that it's there right now, because there is a clear distinction between the knowledge that I have and the knowledge that most people lack. So I have knowledge of something which it's possible to doubt and yet my knowledge is not based on up-to-the-minute experience. I don't have a problem with that. It's an interesting observation.
Tate September 21, 2022 at 12:39 #741452
Reply to Cuthbert

Yet you have neither empirical nor logical proof. That's the interesting part.
Darkneos September 21, 2022 at 22:11 #741545
Reply to Tate You do have logical proof though and to a lesser extent empirical.
Tate September 21, 2022 at 22:15 #741547
Quoting Darkneos
You do have logical proof though and to a lesser extent empirical.


What's the logical argument?
Daniel September 22, 2022 at 02:51 #741605
Reply to Tate

Imagine an infinitely large line of people or a line of people that goes all the way around earth. Every person in each scenario has a person in front and another person behind them; in addition, each person is in front and behind two other people. Imagine you are the leftmost in a group of three people from one of these lines. How would you explain that the person in front of you is the person in front of you when that person is in the "behind" of someone else? In fact, how would you explain your existence when you are someone else's behind?
Agent Smith September 22, 2022 at 06:25 #741631
If existence is tied to perception (existence [math]\to[/math] perception), what we don't perceive doesn't exist (modus tollens). However, what is behind us is what we can't perceive i.e. it is a limitation imposed by our body structure (eyes are looking in one direction only) and that's what we call a confounding factor that simply can't be removed from the equation much to our disadvantage. The point then is to distinguish two kinds of non-perception viz. don't & can't kinds. What I don't perceive (front of us ) doesn't exist, but what I can't perceive (behind us) may exist.

Furthermore, [s]Perception [math]\to[/math] Existence[/s] [Hallucination (mental illness/drug-induced)]. In other words there are no sufficient conditions, if perception is our benchmark, to decide whether something exists or not. We are left with only the ability to disprove existence (existence [math]\to[/math] perception) via modus tollens, but not prove it.

As is obvious to the reader, contrary to what we've been thinking all along, we don't have a definition of existence if perception is our standard/measure. Odd that!

[quote=Gorgias] Nothing exists [...][/quote]

Skepticism ne plus ultra.
Tate September 22, 2022 at 11:13 #741685
Quoting Daniel
Imagine an infinitely large line of people or a line of people that goes all the way around earth. Every person in each scenario has a person in front and another person behind them; in addition, each person is in front and behind two other people. Imagine you are the leftmost in a group of three people from one of these lines. How would you explain that the person in front of you is the person in front of you when that person is in the "behind" of someone else? In fact, how would you explain your existence when you are someone else's behind?


Yes, we can't delete "behind" from the English language. Our philosophy super powers aren't that strong. :groan:
Ciceronianus September 22, 2022 at 15:32 #741748
We spend so much time wiping our behinds, I don't see how we can't know that we each have one. If, then, we each have a behind, it follow there's always one behind us.
Cuthbert September 22, 2022 at 15:35 #741749
[quote=Velvet Underground, Sunday Morning]Watch out, the world's behind you
There's always someone around you who will call
It's nothing at all[/quote]

https://www.youtube.com/watch?v=N3Oc9C3EHLo
Alkis Piskas September 22, 2022 at 16:42 #741757
User image
Darkneos September 26, 2022 at 21:53 #742756
Reply to Agent Smith I wouldn't say nothing exists.
Banno September 28, 2022 at 22:02 #743197
Quoting Ciceronianus
We spend so much time wiping our behinds, I don't see how we can't know that we each have one. If, then, we each have a behind, it follow there's always one behind us.


Hmm. While the philosophical point stands, I'm not too keen on the use of collective pronouns here. You are on your own as far as arse wiping goes.
Darkneos August 28, 2023 at 01:52 #834111
Quoting Agent Smith
As is obvious to the reader, contrary to what we've been thinking all along, we don't have a definition of existence if perception is our standard/measure. Odd that!


Except that we do. Also good work showing how useless this sort of thinking is in day to day.

Looking back at the guy in the answer he's obviously wrong. Mirrors aren't an illusion, they show behind us because we can't see it. The part about memory doesn't change that either. Just because we can't remember what was in front or behind doesn't mean there aren't such things. not to mention is there is no behind you a car would never work.

Plus like I said before, there are dire consequences to thinking like the the guy in the quora answer. Break real hard on a busy highway and see how well that holds up.

It's actually kinda interesting how divorced from day to day reality a good deal of philosophy is, at least this topic anyway. I can't believe I took it seriously.
jorndoe August 28, 2023 at 02:58 #834119
Quoting Darkneos
How do we know there is a behind us?


:D Might just turn around and take a look. Has this ever failed you? (Would you expect something more than that?)

Darkneos August 28, 2023 at 04:00 #834132
Reply to jorndoe that was my initial response to what they said, however after further thought I have no reason to take the person in the Quora answer seriously.

No amount of skepticism changes the fact that I haven’t been failed by “recognizing” there is a behind me. If anything listening to that person actually hurt my ability to remember stuff and almost caused a few accidents