this reminds me of Descartes's. "I think, therefore, I am." He uses something non-physical, such as thoughts, to prove something physical, himself. Therefore, even if he is mistaken in what he thinks he is (he may not realize that he is a brain in a vat), he cannot be mistaken in thinking that he exists, in whatever form. — Beverley

Descartes' certainty of knowledge comes from his doubting. Without doubting, no knowledge. Whenever there is a reason to doubt, don't hesitate to doubt before coming to conclusions.
It must had been a philosophical methodology for acquiring truths for him.

so we can use a non physical thing, light, to prove a physical thing, the object. — Beverley

I think, therefore I am. I am, therefore the world exists. Yes, it seems to work.

For us to see anything, light must reflect off a physical object. Even if you are in the desert and seeing a mirage, what you see is still the result of light waves being reflected off physical things, if only air particles. I think this makes sense…. — Beverley

What we are seeing is the reflected light, not the object itself, and it does give possibility of illusion with the visual perceptions. Therefore scepticism comes handy even in the practical life let alone philosophy. Yes, it does make sense.

We see the reflected light, but if there was nothing to reflect off, then we would not see the light. Therefore, it seems as if just the fact we can see the light means that there must be objects around us. We may see the objects differently from what they actually look like, meaning the images may be distorted, but there must be some sort of physical objects for us to see images of them.

So, at night I open the book, and start reading it. Due to the darkness I must switch on the light before reading it. With no light on, there is no vision. It is total darkness. I cannot even see the book. It is just total darkness. When the light is on, the book is visible. I can read it. In this case, was I seeing and reading the book, or was I seeing and reading the reflected light from the book?

So, at night I open the book, and start reading it. Due to the darkness I must switch on the light before reading it. With no light on, there is no vision. It is total darkness. I cannot even see the book. It is just total darkness. When the light is on, the book is visible. I can read it. In this case, was I seeing and reading the book, or was I seeing and reading the reflected light from the book? — Corvus

You were seeing light being reflected off the book. You would only see light directly from the object if it was luminous, meaning that it emits its own light. The filament of a light bulb is an example of a luminous object; it emits its own light. This light then bounces off the book to your eyes, enabling you to see an image of the book.

Objects can absorb, emit, transmit and reflect light. When objects absorb light, they don’t necessarily absorb all waves of the visible light spectrum, they reflect some. So, for example, if you turned on your light to read your book, and you looked down, and the cover of your book looked blue, this would mean that your book cover had absorbed all the waves of the visible light spectrum, apart from blue. (absorbing red, orange, yellow, green, indigo, violet, and reflecting blue light waves back to your eyes) Since your book is not transparent, you cannot see the light inside, you only see the light reflected from the outside, in this case, blue.)

(reflect = something bounces off the surface, absorb = something goes inside, emit = something moves back outside after being inside, transmit = something passes through)

An object that looks black absorbs all the waves of the visible light spectrum and does not reflect any light waves. (We can only see a black object because it contrasts with the light around it. Therefore, when you read the text of your book, you are noticing the lack of light compared to the light around it) Actually, what usually happens is, when light waves are absorbed, the energy is transferred to the electrons of the atoms, and they increase in energy levels. In some objects, so much energy is absorbed that there is excess energy, which is then emitted out again in the form of light. These objects are described as being luminous objects, and they are where visible light originates from, like the Sun, or the filament of a bulb.

The red side of the spectrum includes longer waves, which are less energetic than the shorter blue/indigo/violet waves. When electricity flows through the filament of a bulb, it transfers excess energy to it, and hence, the filament begins to emit that energy in the form of light.(and heat etc) At first, less energy is emitted, as less electricity has transferred energy to it. At this stage, the filament will emit the shorter, less energetic red light waves. However, after time, more energy is transferred from the electric current and the filament will glow orange and eventually blue/white. At this stage, it is emitting the shorter, more energetic blue waves as well.

But what I was trying to say (before I ended up writing rather a lot about light waves!) was that if we can see images of objects, there MUST be objects/physical things around us, that are either emitting their own light, or reflecting light emitted from other objects. This would seem to prove that there are objects around us.

Hopefully this all makes sense, and I haven't over complicated things :/

But what I was trying to say (before I ended up writing rather a lot about light waves!) was that if we can see images of objects, there MUST be objects/physical things around us, that are either emitting their own light, or reflecting light emitted from other objects. This would seem to prove that there are objects around us.

Hopefully this all makes sense, and I haven't over complicated things :/ — Beverley

Great post.  Thank you for your substantial post on the light and wave reflection mechanism for visual perception.  It is a good argument with no complication at all.

Yes, things exist, and we know they exist by perceptions.  As soon as we open our eyes in the mornings, the world appears to us in our sights.  

Some sceptics would demand to prove the world exists, because it might not.  They were the extreme sceptics who believed that things don't exist. the world doesn't exist, and if it did, we cannot know or prove that they exist.  Of course, their claim is wrong.  Things and the world exist.

But the academic sceptics would say that the world exists, but what are the grounds for our belief in  their existence?  or How do we justify our belief in existence?  So it is not total denial of the existence or knowledge, but attempting to find out the nature of our belief in the existence.

Do we believe in the existence of the world and objects by just visual perception alone?  Or do we need more than what we see to believe in the continued existence of the world and objects in the world?

My answer to that question was, when I am not perceiving the world, there is no reason that I can believe in the existence of the world. I may still believe in the existence of the world without perceiving it, but the ground for my belief in the existence is much compromised in accuracy and certainty due to lack of the warrant for the belief. — Corvus

I thought about this a lot when I first found this forum. I walked around with this in my head for a few days. I even made a whole Word Doc of notes on my thoughts. Then I realized that I couldn't post anything until I had been accepted into the forum. Now I have, here are some of my thoughts:

If we are concerned with the 'ground for' your belief, then I assume what you are looking for is some justification.

Firstly, if you are justified to believe in what you can perceive in front of you, then doesn’t it follow that if you have never perceived the world not existing, then it is not justified to believe in that?

(At this point, I tend to have an argument with myself to see what holes there are in my reasoning. This was the result)

You may then argue, 'But aren’t you then relying on memory? I mean, maybe you did perceive the world not existing, but you just cannot remember it, and, as we all know, memory is unreliable."

Perhaps, but it doesn't seem logical that you would forget something as significant as the world not existing. Therefore, it seems more justified to believe that this never happened. Furthermore, if you cannot trust your memory, then you cannot trust your memory of what you perceived in front of you just now, or any time, or that perceiving something in front of you ever even happened.

"But," you may say, "you can trust it at the moment it happens."

Hmm, but the moment it happens, it becomes the past, and then you are relying on memory, which cannot be relied on.

"But what if memory gets less reliable the further into the past something is," I hear you say.

Well then, how can you tell how far into the past something is if you cannot rely on your memory? Something may seem to have happened recently, but you just forgot that it happened a long time ago, and therefore it cannot be relied upon.

"Okay but, what if you experienced nothing, but you were so traumatized by it that your brain blocked it out?" you may say.

In this case, there is no world, but you are unaware of that. Therefore, as far as you are aware, you have never experienced the world not existing, and your reason for believing in the world is justified.

Is that enough justification?

He uses something non-physical, such as thoughts, to prove something physical, himself. — Beverley

Just a small correction: Descartes says that he is distinct from his body. So he uses instead his thoughts (mental) to prove something mental, himself.

Descartes says that he is distinct from his body. So he uses instead his thoughts (mental) to prove something mental, himself. — Lionino

I'd forgotten about that. But, if he believes he is distinct from his body, then isn't he only thoughts? What else could he be?

In a way, you could say he is thoughts, but what he say he is is the res cogitans, the thinking agent, or his soul.

In a way, you could say he is thoughts, but what he say he is is the res cogitans, the thinking agent, or his soul. — Lionino

Okay, you've got me thinking now. So, is it just his belief that he is the res cogitans? How did he know he wasn't simply the thoughts?

So, is it just his belief that he is the res cogitans? — Beverley

In the same way that it is just Kant's belief that existence is not a predicate, or Plato's belief that universals are real, yes.

How did he know he wasn't simply the thoughts? — Beverley

The mind basically amounts to every mental operation, or rather, the things that hosts these mental operations. So the mind contains the thoughts.

So the mind contains the thoughts. — Lionino

What if there is no container?

What you are asking is a common wonder about the ontology of Descartes.

I will first say what it means for Cartesian philosophy. As far as I know, he does not directly address the question of the vessel of thoughts, but from his philosophy, we have things such as atributes, modes, and substances. Thought would in fact be an attribute of of the thinker. He says in a letter to Regius:

You agree that thought is an attribute of a substance which contains no extension, and conversely that extension is an attribute of a substance that contains no thought. So you must also agree that a thinking substance is distinct from an extended substance. — Descartes

The SEP interprets that attributes and the substance are in fact the same thing, only different in our understanding:

Attributes are in fact what make existing substances intelligible to the human mind. He reaffirms this in Article 62, where he says that there is only a distinction in reason between an attribute and an existing substance. — SEP

According to the fragment, thought would be the as the thing. Reading Descartes however we would not fully agree with that, reading even the material that the SEP quotes to support such a statement:

But when it comes to knowing whether any of these substances truly exist, that is, whether they are present in the world, I say that it is not enough for them to exist in this way for us to perceive them, since in themselves they do not make us discover anything that awakens any particular knowledge in the world. our thinking. It is therefore necessary that it has some attributes that we can notice, — Principles of Philosophy part 1 section 56

For example, because any substance ceases to exist when it ceases to last, duration is only distinguished from substance by thought. — Principles of Philosophy part 1 section 62

I don't think it makes sense to consider duration to be the same as substances.
We would think instead that an attribute is something that emanates from the substance. As he says that extension and divisibility is of bodies, thought is of the thinker, along with other things, such as feeling and intuition. So attribute would not be used much differently from its everyday meaning: something that composes and characterises X, but does not subsume X — there is no substance without duration, but duration is not substance.

What it means outside of Cartesian philosophy. Bertrand Russel's criticism of Descartes touches on the definition of "I". Some people retort that the "I" can simply be defined as the thoughts themselves, but from there we have other issues. I have written a bit about it, though of course not in English. I have Google Translated it:

• 1. I am the thing that thinks. But is there something beyond thought? If not, I am the thought; If so, what is it?
  I am either other thoughts, or an external structure.
• 2. I am the thought. But how can I be thought? If I am thought, "I think, therefore I am." implies that thoughts think. If thoughts do not think, I am not "I think, therefore I am."", but something else. If thoughts think, I thought and came into existence, but from this it would follow that I existed before thinking myself, therefore I would never come into existence, because my existence would depend on my action. I could be a previous thought that thought "I think, therefore I am.", which would already qualify as an external structure, and this previous thought simply arose and does not require a thinker because it does not state "I think." — may or may not have prior thought.
  
  • 2.1. I have no previous thinker, I am this chain of consecutive thoughts which begins with a thought that only arises. This finite multi-thought begins, produces "I think, therefore I am.", remembers it, affirms it, and dies. This multithought would be the external structure.
  • 2.2. I have a previous thinker. Is this thinker me, another being, or another thought?
    
    • 2.2.1. It's me, so I'm a chain of thoughts that regresses to the past. Is the current finite or infinite?
      
      • 2.2.1.1.If the current is finite, I am a finite multi-thought, an external structure. But how does one thought become the next?
        
        • 2.2.1.1.1. An external structure causes the changes.
        • 2.2.1.1.2. They simply become, and causality is not necessary; I would therefore be this purely uncausal finite chain of thought.
      • 2.2.1.2.If it is infinite, I would have infinite thoughts, but I don't have them; perhaps it was therefore an infinite stream of thoughts with limited memory, this stream plus the limited memories, which may be part of the thought and therefore part of the stream itself, would be the external structure. But how does one thought become the next?
        
        • 2.2.1.2.1. An external structure causes the changes.
        • 2.2.1.2.2. They simply become, and causality is not necessary; I would therefore be this uncausal infinite stream of purely thought with limited memories.
    • 2.2.2.Another being, therefore another being exists besides me, thought, and this being could be identified with 'I', which thinks "I think, therefore I am.".
    • 2.2.3.Another thought, which implies that something must have thought it, and so on infinitely. However, this infinite stream of thought can be identified with 'I'. (Only if the thought that caused the other are the thoughts in my memory, if not, it cannot be identified with me)
• 3. I am an external structure. But what attributes does this external structure have?

However, even more directly and simply, the initial objection is “I am 'I think, therefore I am.', and I think”, therefore, if the agent is thought, it could not say “I think” nor “I exist”, as it would only pass to exist as soon as thought itself ceased, resulting in a paradox. If thought is something that occurs instantly, thought could not be experienced, as it would cease to exist as soon as it concluded.
One answer to this would be, if I am a pure stream of thoughts, finite or infinite, how can I think about my own existence — and therefore see it — without it first ending, and then ending my existence? It follows that I can only see part of myself, and then identify “I think, therefore I am.” with pure infinite current retroactively changes the only possible statement of “I think, therefore I am.” to “I think, therefore part of me exists.”. However, every part is included in a whole, and establishing the existence of a part establishes that of the whole, therefore “I think, therefore part of me exists.” implies “I think, therefore my whole exists.”, which would just be “I think, therefore I exist.”.
In short, it is possible to identify thought with the agent himself. And in this case, it implies that I am an external structure, or that I am a pure stream of thoughts, and those thoughts themselves would be something other than “I think, therefore I am.”.

I have not checked the translation. If you are interested, I will do it if there are any confusion to be cleared up.

Whoa. There’s some serious paralogisms you got goin’ on right there.

Well done, I must say.

Not so sure about what the conclusions might be, but that’s ok.

There is but energy in the forms of frequencies and vibrations not all of which we experience. Objects are energy forms in the way of manifested objects because that is the way we experience given energies. Our given apparent reality is a relational fact, relative only to the biology perceiving it, in other words, energy affecting biology, biology being effected, and projecting apparent reality, a biological readout, not unlike that of a calculator.

We know that there is no color or sound in the real world, it is [...] — boagie

Hmm... Are you saying that our experiences are not part of the real world? Sure, they might be existentially mind-dependent, yet aren't (also) minds part of the world? :chin:

Experiences are the effects upon biology of the energies around us, we do not experience the reality of this, we experience its effects, and this is what is called apparent reality. In a sense, no the mind is not of the world, it observes the objects of the world; just as you experience your body to be in the world. You do not experience your mind. You experience what comes into and goes out of the mind not the mind. Apparent reality is a sum of biological reactions or a biological readout. We don't experience what is, we experience how what is affects and alters our biological natures.

↪Banno How is the existence of an outside world a silly question? It is quite the recurrent question in the history of philosophy. — Lionino

Certainly it is. (Only that I would say, "a recurrent question".)

We do not experience what is real, we experience what is, as it affects us altering our biology. Apparent reality is a biological readout. It is a melody if you like, played upon us by the energies that surround us, the melody is that of apparent reality. These effects upon us are experiences, understandings, and meanings of what it is to be affected. We are an emergent manifestation, as are our understandings.

"Okay but, what if you experienced nothing, but you were so traumatized by it that your brain blocked it out?" you may say.

In this case, there is no world, but you are unaware of that. Therefore, as far as you are aware, you have never experienced the world not existing, and your reason for believing in the world is justified. — Beverley

But a sceptic might say, how can I be 100% certain that my beliefs, memories and awareness are accurate? There are possibilities that the beliefs, memories and awareness could be wrong.

The mitigated sceptic would say that he is not denying the existence of the world, but he is not sure if the awareness, memories and beliefs of your perceptions could be somewhat different or wrong from what you took to be the case. He would then ask to prove that your belief, memories and awareness are 100% free from the possible illusions and errors.

And there is another issue, which the sceptic might demand you to clarify, and that is the definition of the world that you claim to believe in to exist i.e. does the world that you believe in to exist, include the whole universe with all the celestial objects such as the stars, planets, the blackholes, the galaxies, comets and also the all the micro biotic entities such as molecules of all the plants, animals, fishes in the sea etc plus all the people in the world, and the countries on the earth as well your town that you live in ... etc, or is it something totally different from all these?

There is but energy in the forms of frequencies and vibrations not all of which we experience. Objects are energy forms in the way of manifested objects because that is the way we experience given energies. Our given apparent reality is a relational fact, relative only to the biology perceiving it, in other words, energy affecting biology, biology being effected, and projecting apparent reality, a biological readout, not unlike that of a calculator. — boagie

Does this mean that what exists beyond our biological sensibilities doesn't count as the part of the world? Should only the objects which are possible to be experienced by the biological senses be the world and part of the world? Is that your point? If it is so, then we might have to drop all the scientific knowledge as non-reality which belongs to not this world, but in some possible world. That would be a strange world.

There is what is called apparent reality, and there is what is called ultimate reality. Apparent reality is your everyday reality, while ultimate reality is the energies in the forms of frequencies and vibrations, this is a place of no things, just energy. Apparent reality is biologically dependent, it is how these energies at least some of them, affect us by altering our biological natures. This is what we call experience,
meaning, and the manifestation of objects, remember, ultimate reality is a place of no things. Those energies that we don't experience, for us do not exist, though I imagine some affect us without our being conscious of them.

So you divide the world into apparent and ultimate reality. So, you are not denying the biological sensibility independent world as non-existence. Yes, that sounds reasonable.

It is weird I know, but the melody the energies play on their instrument is the biology of life, it is a relational reality, constituting the effects of these energies in altering the nature of one's biology. This process is experience, knowledge and meaning to the conscious subject. It is the conscious subjects apparent reality, real as real gets to the biological entity. Apparent reality exists only for biological life and its consciousness, remember, ultimate reality is a place of no things.

Not so sure about what the conclusions might be, but that’s ok. — Mww

I just read the translation and it surely butched some 40% of what I wrote, but the meaning can still be understood partially.
I am not sure if it is clear from the g-translated text, but the conclusion ultimately is that there is not just "thoughts", but there is something thinking that thought at least, and that something can be defined as an external structure, and that external structure can be, in basically all cases, defined as "I". So, I think therefore I am does hold in Cartesian philosophy and can still hold outside of it.

Certainly it is. (Only that I would say, "a recurrent question".) — Alkis Piskas

Right. The use of 'the' is just an idiom (with the butchered meaning of the word instead of the real meaning) in English, see.

Apparent reality exists only for biological life and its consciousness, remember, ultimate reality is a place of no things. — boagie

What is "a place"? Is it some location on the earth such as town, city or a well-known location, or a house, building, temple or even church?

What do you mean by "no things"? What are they in actuality?

The modern physics tells us that all there is energy, Tesla agree whole heartedly. So, if all there is, is energy then there are no things. There are only things for biology, experiencing these energies and processing them biologically gives one a world of objects, an apparent reality. This by the analogy of a melody is heard only by the subject consciousness, it is real to biological life, but it is just energy. The place is the world, a world devoid of objects in the absence of a conscious subject. This is why I say, there is no such thing as something being objective, think of apparent reality as a biological projection, a biological readout.

The place is the world, a world devoid of objects in the absence of a conscious subject. This is why I say, there is no such thing as something being objective, think of apparent reality as a biological projection, a biological readout. — boagie

Is the world devoid of objects in the absence of a conscious subject, a part of the actual world? How could a conscious subject access or understand the world, if the conscious subject is absent from the world?

The modern physics tells us that all there is energy, Tesla agree whole heartedly. So, if all there is, is energy then there are no things. — boagie

It looks to me like you are throwing the baby out with the bath water. Some forms that energy can take are highly stable on the scale of human lifetimes. Energy in such stable forms (and particularly macroscopic agglomerations of such energy in stable forms) is what we conceive of as physical things. Might it make more sense to refine one's notion of things, rather than try to do without a notion of things altogether?

For a biological entity there are things in its apparent reality, but apparent reality is an emergent manifestation particular to that biology. If you wish to experience a different reality alter your biology. The world, the cosmos plays biological life as its instrument, and the melody played on this instrument is apparent reality. So, for life forms there are things, but in ultimate reality there are no things, things/objects are biologically dependent. As Tesla is famous for saying if you wish to understand the world, think in terms of energy, frequencies, and vibrations. Apparent reality is emergent in this sense, its composition is the reactions of biological consciousness to these energy frequencies and vibrations. It is not unlike a dream world, a world relative to life's biological nature. People talk sometimes of the possibility that life lives in a simulation this is correct, its own simulation, biological reaction is how we are the world.