"I Think Therefore I Am", "The Brick Wall", and "Objectivism"

Firstly, I would like to say that it seems like “I think therefore I am” proves one exists, but only to oneself. Last time this came up, this led to a very interesting debate. Forgive me if that similar thread still exists. I am pretty sure the one I am thinking of got destroyed in the hacker incident. I would do a search, but search won’t give daddy any love today. The thread was about proving one’s self exists - if I remember correctly. The classic “I think therefore I am” came up, which was disputed as proof of existence. The reasons were interesting, but the specifics escape me.

Secondly, I am interested in re-running that debate because of a certain phenomenon I keep running into, which I affectionately call “The Brick Wall”. The brick wall is when someone says something like “Prove that chair exists.” in response to a statement like “Belief without proof is irrational.” Now, to prove that chairs exist, one must ask “What is proof?” It seems like it is a reasonable amount of evidence. Then comes “What is evidence?” - Which is a problem. I (typing I in italics is fun), would say that a reasonable standard for evidence is that it must be something that can be perceived, shared, tested (in repeatable tests), and be able to assist in making predictions. I think my definition may be a bit lacking here, so I am hoping for some help there.

So, evidence defined, one can prove the chair exists by presenting reasonable evidence such as all of your past experience with chairs. One could interview a hundred people (although anyone but an idiot need only ask their parents at a very early age) to confirm their experience with chairs. One could pick the chair up. One could take a photograph of the chair. The chair seems proved to me. Still, my brick wall slinging friends will point out that until I have sat on the chair, I have not proved it’s existence, and some will say it is not proven even then. So to believe the chair will support me is now somehow just as irrational as me believing that monkeys will fly out of my butt - assuming, of course, that belief without proof is irrational. Then, in come the axiom philosophers stating that “all systems of knowledge are equally valid”.

I really have a hard time with this line of thinking. Doesn’t this effectively destroy proof as a whole? Surely there are things we can prove! Surely there is a range that can be called reasonable! The definition of evidence should not have to change based on the subject. While going through life, we must separate the scams from the butter, and we use reason for this. We create a standard of evidence which we need before we accept something. Why is this somehow invalid when dealing with issues (metaphysical) which do not meet that standard of evidence? Why must all evidence suddenly become incapable of proving anything?

I have a numer of devout fundamentalist christians in my family (southern baptists no less), and we have always debated ferociously with each other. I also have a number of friends (who associate themselves with no religion) who love to debate anything and everything. I run into this Brick Wall with them in matters which don’t regard religion in any way - so please don’t inerpret this as me saying this is a “religious” thing. It is a debate thing. I struggle with it to the point of frustration and then give up. I would like to get some advice on how to work through this with people using reason instead of throwing my hands up in the air and rolling my eyes.

I did a search on “debate” and “axiom” and came up with a great link:

Objectivism & Debate

Wow. That’s a brain full. I’m going to go re-read it a few times. If you have the time, read pages 2 through 6. I am very interested in what people’s thoughts are on this issue.

DaLovin’ Dj

Consider the extra difficulty presented to the monkeys by your act of sitting in the chair.

Sorry, I just had to say it.

My feeling is that what matters is whether it works or not, that is, you can hold to whatever view you like, as long as it seems to be consistent with what you perceive.

I think I am, therefore I cannot be objective about my existence, I just deal with what I perceive it to be.

Sorry again if this is nowhere close to what you wanted. If you say that belief without proof is irrational, I just have to reply that that is the definition of rationality, but not necessarily an argument for it.

Most of these problems come from a strange view of philosophy. I think many people read a little philosophy, learn that certain things they thought were certain are not certain, and come to the conclusion that nothing is certain.

The argument seems to run thus -

(1) In order for anyone’s belief to be knowledge, that belief must be justified. (This is in line with the generally accepted philosophical definition of knowledge as “justified true belief”.)

(2) Subject A believes that (1) is true.

Subject A believes (1), but does she know (1)? Only if she is justified in believing it, and only if it is true.

Let’s assume it is true. Let’s call whatever it is that justifies A’s belief in (1) X. For A to know X, (since (1), as we are assuming here, is true) she must have justification for X. Let’s call this Y. But wait! How does A justify her belief that Y is true?

This appears to lead to an infinite regress (a Bad Thing[sup]TM[/sup]). Whatever form of justification that could be thought up, someone could just ask, “Well, what justifies using that as justification?” Hence, any belief would require infinite justification. Since such a thing is not possible (either because such an idea is incoherent, or does not exist, or because a finite mind can never justify things infinitely) then knowledge is not possible.

If we allow that (1) is true, then the conclusion seems inescapable. (At least at first glance.)

But there are some things that make this less devestating than it seems.

First, what if (1) isn’t true? What if knowledge is possible but in a different way? This could be the case, although most philosophers would not like scrapping the idea of justification. It is unclear what other sort of knowledge might be possible. This is not generally considered a palatable option.

Second, let’s say the argument’s conclusion is true. Are we justified in believing that it is true? If no, then although we don’t know anything, one of the things we don’t know is that we don’t know anything! In other words, if someone tells you that you know nothing, ask then how they know. :slight_smile:

Let’s say the argument’s conclusion is true, but we are justified in believing it. Well, then there is at least one thing we can know. But the conclusion was that nothing can be known. Thus the argument entails a contradiction and can’t be valid.

There are other arguments against knowledge, though. Each must be addressed on its own merits.

(Sorry I have to cut this a little short - I’ll try to write more later.)

I can understand why you’re frustrated. Sometimes you want to argue about who really got more votes in Florida, without having to call into question all of epistemology and metaphysics. The “Brick Wall” seems like a weaselly way to avoid any substantive questions.

But here’s the flip side. It would be nice if “proof” and “evidence” were absolutes we could all agree on. But we don’t all agree on those things. So, when the question hinges exactly on a question of what we mean by proof or evidence, then we’ve got to stop and figure out what we mean by those things. And if we can’t agree, then we may not have anything useful to talk about except epistemology.

Let me suggest that your definition of proof and evidence is too restrictive for some of the things that you probably want to include. And that’s the trap. Widening your standards allows too much to be proved–you have to accept some things you don’t really want to accept as consequences of your epistemology. Tightening your standards forces you to reject things you do want to accept. Or worse, accept them without valid proof or evidence, which means I get license to believe anything I want to, too.

Also, I would suggest that maybe we don’t really want to insist that “the definition of evidence should not have to change based on the subject”. The standards of proof and evidence that we require in math, the natural sciences, law, and history are all adequate in their fields, though they are quite different.

Consider also that we bring our emotions to any such debate. The standard of proof we require for those things we want to accept is much lower than for those things we do not want.

kg m²/s²

I think what you, dalovindj want is an objective reality, that is not determined by our perception, but that can be discovered by our perception. OK, let’s work toward that.

What is reality? It seems to me to be a (really big) set. It’s a set of all things that are true. So I’m going to treat it as a set, and I’m aware of the flaws of this approach.

Reality is a set, which is closed under certain operations. What are the operations? Let’s call them the “laws of reality” (I could use “laws of nature”, but that’s suggestive). By “closed under”, I mean that if you apply the laws of reality to real things, you always get real things. You can never arrive at something which is not reality when you start with real things.

In math, such a set is a fixed point of the operations. A fixed point of a function f is a value x such that f(x)=x. There may be multiple fixed points. Two particular distinguished fixed points are the least fixed point and the greatest fixed point. A least fixed point is one that is less than or equal to all other fixed points. A greatest fixed point is one that is greater than or equal to all others. (Obviously, we need an ordering to define “less” and “greater”. Ignore that.)

We know how to calculate fixed points (provided f has certain properties, which I won’t elaborate). We can compute the least fixed point by starting with nothing. Throw in everything that can be derived by the definition applied to nothing (these are the things that are immediately true of the “laws”, sometimes called “axioms”). Now, apply the laws to this set, and throw in every new thing that arises. Keep going. Iterate this process (possibly infinitely many times) until it converges. When it does, it will converge at the least fixed point (textbooks will use the phrase “least set closed under…”). At iteration n, we will end up adding all things that are derivable in n steps by the laws.

We can calculate a greatest fixed point by starting with everything. Throw out all things which are directly contradicted by the laws (i.e. contradicted by direct observation). Now, throw out everything in this set which is contradicted by applying the laws twice (contradicted by “two observations”). At iteration n we throw out everything that is contradicted by applying the laws n times. This process converges to the greatest fixed point.

These correspond to two approaches to computing our knowledge of reality. The least fixed point approach starts with nothing and only concludes what is necessarily true. Initially, assume nothing is real. This is similar to the approach you (dalovindj) advocated in that other thread. In logic, you would start with the axioms, and generate all theorems that could be proven. Obviously, there is a (very big) wrinkle. We don’t know the axioms or the laws. If you presume that you can trust your perception (which I know you do) and that you can trust perceived laws, then you are effectively constructing your reality based on the observations and the laws that describe those observations. I use “constructing” in a mathematical sense (it’s a term algebra :slight_smile: ), not to suggest that your perception or reasoning makes reality in any way.

The greatest fixed point approach starts with everything, and discards all things that are contradicted. This is similar to what I advocated in that other thread. Assume that everything is real. Then, discard things that are contradicted by our perception, or which are impossible by the laws. Again, same wrinkles. Trusting our perception, we are effectively defining our reality based on our observations.

The fundamental difference between the two is that the least fixed point can never include the infinite (unless we observe it directly). That’s not a really big flaw if you don’t believe that actual infinites exist. If we were talking about religion, I would say least fixed pointing is incapable of divining the existence of God, even if he exists, and therefore is not the “best” approach to knowledge.

Both views of reality are consistent with the reality (that’s what it means to be a fixed point). As we learn more about that reality, the least fixed pointer adds new stuff to his model of reality, and the greatest fixed pointer removes stuff. If our perception is adequate to comprehend all of reality, and there really is a single objective reality, then both approaches will converge to the same view of reality.

I personally don’t think that we can comprehend a model of all of reality–I think reality is too big for our brains. Whether this is possible or not isn’t too important, unless we thought we were close to achieving it (like in our lifetimes). The difference between a least and a greatest fixed point approach to computing an approximation of reality is that the least fixed pointer will not believe everything that is true. The greatest fixed pointer will believe some things that are not true.

So, you might choose an approach based on which offended you more: not knowing everything that was true, or believing some things that were false.

There is another real difference that arises if we turn out to be incapable of comprehending reality. It is that the least and greatest fixed points are not equal. We don’t have any way (as in, are fundamentally incapable) to determine what is the real reality. Reality may be either of these choices, or it may be some other fixed point between the two–we just can’t know.

If you felt that reality was defined exactly by what we were capable of observing to be true, then you would choose least fixed pointing; but this seems to imply that reality is not objective, after all. If you felt that reality must of necessity include all things that could not be disproven, you would choose greatest fixed pointing. It seems that, in a universe which is not perfectly knowable, neither approach is ideal.

And that leads to the way that most of us actually approach the question of knowledge. We perform “chaotic iteration”, sometimes adding things to our reality that are “proven” to our satisfaction, and sometimes removing things that we do not believe in. This kind of reality, a universe that is not perfectly knowable, means that we will all end up with different, consistent views of reality.

What I’ve neglected is fairly important: we don’t even all have access to the same observations. Even a least fixed pointer can believe in God, if they thought they had reason to trust a perception of God. Clearly, a (mostly) least fixed pointer such as yourself that never perceived any hint of God would not believe in God, and would be perfectly rational. A (mostly) greatest fixed pointer, or a (mostly) least fixed pointer who had perceived what they thought was God, would have a quite rational belief in God. I use God as you did, only as an example. I’m not suggesting that any belief is correct.

This is long winded, but I suppose that’s what the thread calls for. If you really read all that objectivism stuff, and then got this far, I’m sorry I did it to you. The conclusion, I think, is that you should feel fairly safe if you insist that debating opponents must accept that which they feel is proven and reject that which they feel is disproven. That doesn’t get you too far, but I think it might make it clearer who isn’t even worth wasting time on, and who is just computing a different fixed point approximation to reality.

kg m²/s²

PS: I’m aware that the issues I dodged are perhaps greater than the ones I addressed.

I apologize if this has been mentioned before, I’m afraid I merely skimmed the thread. It is impossible to prove the existence of anything, except, perhaps, one’s own consciousness. Why? Look at that keyboard in front of you. How do you know it exists? You can see it, touch it, and taste it. However, it is impossible even then to be certain of its existence. The reason is that all such observations rely on the mind. For all we know, the entire world could be a form of hallucination that the mind has created. True, it is possible that an external world could exist, but I have not yet determined a way to prove whether or not it does. Just for fun, here is an interesting concept: if most people at one time believed the Earth to be flat (assuming, for the moment, that the world is a product of more than one mind’s perception) than was the Earth flat? Did it only become round when people started believing it to be round. Is sanity collective? There are, of course, many other questions associated with this subject, but I choose, at this time, not to list them all.

It assumes what it is trying to prove. “I” is both the subject and the predicate.

Yeah, extreme skepticism.

By doing this you already assume that something exists to perceive. In this case, determining if “it” is a “chair” is a matter of definition (note that I didn’t say a simple matter of definition!). But this is where “chair” fails to find itself, and where the bricklayers can stop you cold. For every definition you concoct, either things will be chairs that really aren’t chairs to you, or things that are chairs to you are ruled out of the definition.

Sure, because what assurance do you have that your perceptions are accurate? Could you not have reasonably proved to yourself that item X is a chair, and then come to find that you are mistaken?

Which axiom? I know several philosophers which would say no such thing.

Dunno if you got to participate in these, but they were fun and somewhat on-topic (not quite, but somewhat).

The Problem of Universals started by yours truly and
Does consciousness/identity need to be continuous? Started by yours truly. :slight_smile:

Definition of terms is essential, and usually overlooked step in logical debate. For instance, when you decide that reality does not include the imaginary, you have eliminated the validity of imagination as a characteristic of any real being. So, you have to go back and redefine reality to include conceptual objects so that there can be philosophical entities like logic, and proof in the first place.

Ah, but now you have done it. Do Unicorns have horns? Of course they do. No, they don’t, both the Unicorn, and it’s horn are imaginary. But if it has two of them, then although it is still imaginary, it isn’t a Unicorn. Beauty? How can it exist? Those who ardently believe in it can’t even define it. Truth itself is not nearly so definite as we might hope, for debate purposes. Real? Homer might never have lived, yet the Iliad still gets published every year.

So, unless you are able to accept a set of definitions, and axioms, purely for the purpose of the debate at hand, then all arguments are indeterminable. And the fact is that each definition will subsume an entire additional list of definitions, some including assumptions of the truth of non-axioms as well.

I recommend dropping a tree on the existentialists, right away, and encouraging every one to pretend they didn’t hear it.

Tris

“There is nothing so absurd but some philosopher has said it.” ~ Marcus Tullius Cicero ~

Actually, I wanted to touch on this a bit:

I have at least heard that it is impossible to determine which knowledge system is “the most” valid. But definitely not that they are all equally valid.

Here is a quote from Libertarian in this thread. I have seen this approach before, but this is the most recent, and the only one I can cite right now.

I am trying to balance my work load with my doping and the workload is getting a little ignored. Alot of interesting points I would like to discuss in here when I get a little more time.

DaLovin’ Dj

Hmm, yes, well, I must vehemently disagree with Lib on that. Certainly some may seem more valid than others, but that measure of validity is made from within a specific set of assumptions regarding “what a system of knowledge should do” and, obviously, presupposes a system of knowledge by which to judge systems of knowledge. Thus, truly, they are all equal in the sense that they are all arbitrarily founded, but clearly by any standard we care to devise any two systems of knowledge will differ on at least one point… and when they do, where does one turn to find out which one is “more” correct?

To avoid such a logicstical nightmare one must remove the concept of “validity” from “system of knowledge”. another brick wall, perhaps?

I don’t think it matters too much whether the universe is ‘real’ or not (what a strange thing to be saying); maybe we are just brains in jars, maybe the entire universe is just and elaborate simulation in which matter, energy, and ultimately complex entities such as ourselves have arisen as a result of nothing more than the inherent possibilities of the simulated universe; maybe we are living the dream of a god, maybe reality is a consistent mass hallucination, maybe it is real after all (whatever that actually means).

It doesn’t matter; all of these things describe the kind of container in which exists our universe; but we are unable to percieve or interact with the container, so in every acceptable sense of the word, the universe is real, or as real as we are.

Well, I was a philosophy major for a bit until I figured out that it was nothing but noise. Anyway…here we go.

First, the “I think therefore I am” arguement has a big problem. The problem is simple, for something to cause an action the object must exist first. “I think therefore I am is” backwards. It shoud be “I am, therefore I think.”

Second, Philosophy, Causality and Quantum Physics. Philosophers seem to think reality is a function of our perception of it. In essence, they think that our perception is ‘required’ for there to be a reality. What they don’t take into account is that objects in the real world will interact with each other with no one present. For an example of this consider the question “If a tree falls in a forrest and no one can hear it, does it make a sound?”. The question has been argued to death. But, as far as I can tell, no one has hit on the problem with the question. The question should be: “If a tree falls in a forrest and no one hears it fall, does the tree falling affect the rest of the forrest?”. The original question assumes that hearing == reality. The second question, the one I posed, assumes that objects can affect each other without a human being there. Regretably, quantum physics has gone down the non-causal road. Shrodengers(SP?) Cat, originally a mockery of quantum theory, is now the standard thought.

Third: Definitions. Richard Feynman, in one of his books, talks about his experience in a philosophy class. They were talking about a ‘brick’ as an ‘essential object’. Feynman asked if the inside of a brick was an ‘essential object’ IIRC. Anyway, debate ensued. Feynman, and I agree with him, thought that trying to discuss anything without defining what the words mean is pointless. So this arguement is pointless.

Geez, and I spent so much time on this.

Slee

Chairs are, too. Do they think?

But that’s the whole problem!–How do you know that? Secondly, not everyone thinks this way. Most feel the world does exist independent of us, but that it doesn’t matter one way or the other, because we can only know about reality via our senses, which obviously require us to be there. Thirdly, still others think that more than just this reality exists (those damn platonists), which of course doubles the problem of knowledge.