I think therefore i am.....

Great Debates
101

Exactly! You are not what you think (or at least, you can’t prove what you are with any certainty). The point of the argument is that the thoughts you have must have some source, whatever it might be.

You are correct that the ‘me’ that my thoughts are coming from cannot be found or percieved directly. (I do seem to be able to think of it, albeit speculatively.) It does have an observable by-product though: the thoughts themselves. Where there’s smoke, there’s fire, so to speak.

The use of the word “I” is just barely more than a convenience: since the only thoughts I can be aware of are the ones that I myself am having, I arbitrarily define them as ‘mine’, a product of ‘I’. And so, even though I have absolutely no knowledge about the actual properties of the thinker, I choose to label it ‘I’ because I have already claimed its thoughts as mine. If you feel this labeling to be a bit presumptious, okay, but the thought experiment has still yielded some result, which is pretty much what dalovindj said: “I think/feel, therefore something exists.”

I think perhaps that poor little ol’ cogito ergo sum has been burdened with more assumed meaning than it actually has the power to back up. It is the commentary on Descartes’s failure to justify the denial of the existence of his own thoughts.

[I wish I had been this clever then]
Prof: “So are you your body or your thoughts?”
Me: “No. Neither.”
Prof: “How so?”
Me: “I wear my body and produce my thoughts. Neither are me.”
Prof: “What are you then.”
Me: “I haven’t the faintest idea, except that it’s able to produce my thoughts.”
[/I wish I had been this clever then]

102

as i said to dalovindj, it certainly seems intuitive that something exists. how could we put our mind around anything else?

you must realize though, that logic cannot be used to conclude this. in order to deduce existence from something, you must first have something that exists. it’s entirely circular.

that “something exists”, in my opinion, is just something that must be taken as granted, because we can’t imagine anything another way. it’s like the trap you fall into if you try to imagine a world without logic: you can’t say anything meaningful about it. but you certainly can’t prove logic is a valid construct without first assuming that it is.

103

Yet another reason why Hume’s epistemology is wholly appealing to me. If you would like I can give some excerpts from the text to outline it. If not I can summarize. If not, well, no problem there, either. :smiley:

104

You cannot start from nothing and deduce from something, adding it in my working forward from something.

You can start with everything and progressively reduce until you reduce no more. Descartes’s approach is unable to doubt the existence of doubts, leaving him with ‘something’.

Different approach resulting in a different result, but not contradictory. You might say that the reductive approach is ‘more powerful’ than the direct approach, meaning that more can be determined from it.

erislover, I confess complete incomprehension of the Hume argument; does it find a flaw in Descartes’s reductive approach, or does it rather show that some other approach is not effective?

105

that you can’t prove something false does not mean it is proved true.

106

The problem Hume sees with implicit self-knowledge is based in his epistemology, wherein knowledge of the so-called real world is based on observation. More specifically, he seperates impressions, which are the direct sensations (perhaps paving the way for a moderately skeptical phenomenology which I have not found, except in Wittgenstein), from ideas, which are assemblages of “abstracted” sensations. Everything we know is made from impressions. The unicorn, an idea, is composed of disparate “parts” we take from either distinct impressions, distinct ideas, or both (or singular).

He challenges anyone to propose a thing which cannot be explained in terms of assembled impressions or assembled abstractions/ideas. I find it to be a rather tough challenge. (interestingly there is at least possibly one strange “reply” I’ve found in the so-called “Problem of the Speckled Hen”)

Thus he dashes any hope of abstracting existence as a unique or clear idea, for if we suppose existence exists (hi, Ayn!) then it must be a “something” we can abstract from every impression. But this is a distinction (existence—impression) without any difference. (For what would distinguish an impression that exists from one that doesn’t? I mean, what do we hope to indicate here? A point TVAA would appreciate, I’m sure, if he’s reading this.)

When we turn to evidence of Self, we must seek the same epistemological path, which is: impression, idea. But to have a constant idea of self that permeates all things, we must have a constant impression of self in all things. This is not a critique of memory or sensation, it is a comment on the construction of self through the process of abstraction and or immediate and intimate knowledge. The source of all ideas, including Self, must come from impressions. If it is always Me doing this, then the Me must be discoverable in all things I do.

Using Hume, the empiricist, to critique Descartes, the rationalist, is a path to sheer madness, I must confess. But I find Hume’s argument much more convincing than Descartes’s. Ultimately I find it more logical (an irony I enjoy).

Ultimately a direct response to the cogito is not found in Hume’s opus. It must be pieced together. For my part, the reductive approach leaving one only with pure thought does not imply “I am” at all, for it makes a distinction (thought, self) without a difference (thought is all that remains). Hume does offer an exposition on scepticism of sensation. I will reread that over the next several days to see if it will aid this enjoyable discussion any.

I do not condemn rationalism in the least. I just don’t agree with it. :smiley:

At the very least, IMO we can consider thought as the tautological definition of self (i.e. - a rule for symbolic substitution). But if we do so, I must confess it seems we are only justified in maintaining that definition so long as we are doubting everything. And that, too, is something I find incorrect.

107

Think of it this way:

Premisies:

  1. If nothing exists, then you wouldn’t be able to wonder wether anything exists.
  2. Yet, you do wonder wether anything exists.

Conclusion, it is not the case that nothing exists.
Conclusion, something exists.

This is a valid logical construction, not a failure to prove something. If you accept both premises, then you are obliged to accept the conclusion.
As for Hume, he’s overlooking a problem: his process of composing concepts from observations requires something to be doing the observation. There is no need for this something to be even capable of observing itself; in which case it would not contribute any data about itself to the knowledge base.

You can say that the concept of existence is derivable from more concrete and eventually observable sensations (which is obviously true) but that is an independent issue from actual existence, which is assumed by the fact that his sensations are being processed.

I do not believe that observation predated thought in any relevant sense; when the spark of cognition first appeared, only after that was sense data collected and compiled into the building blocks of thought.

108

i don’t except both premises. i think your premises can be further fleshed out:

let E(x) = (x exists)
let T(x, p) = (x thinks p)

  1. ~E(x) -> (E(x) & ~T(x, E(x))
  2. T(x, E(x))
    :. E(x)

i think 1) is contradictory. i see no reason to believe that nonexistence implies existence.

do you not agree that “x thinks” is equivalent to “x exists and x thinks”? i guess that’s the heart of it…

109

Of course it does (a comment on the use of the word “observe”). There just doesn’t need to be a constant, consistent, discoverable Self.

Sez you :wink: What is the difference between “processed sensations” and “existence”? Distinction without a difference?

110

erislover:

Then we are agreed! Nothing can be determined about the “self” from Descartes’s argument.

The difference is, one is the idea of existence, and one is existence. If you see yourself in the mirror, then you create an mental image corresponding to the sensed image; this mental image is distinct from your real self. If you were a vampire (bear with me), then you would not cast a reflection; you would be unable to percieve yourself in the real world. That would not mean that you didn’t exist; it would merely force you to find other avenues of showing that you exist, such as cogito ergo sum.

Ramanujan:

What the? Let me translate these logical abstractions back into words.

  1. ~(x exists) -> ((x exists) & ~(x thinks (x exists))
  2. if (not) (x exists) then ((x exists) and not (x thinks (x exists))
  3. if (x doesn’t exist) then (x exists and x doesn’t think x exists)
  4. x thinks (x exists)

??Where did you get that?? 2) ain’t bad, though it’s not accurate; 1) blatantly isn’t what I said.

You want fleshed-out logic: here’s my take.

let E(x) = (x exists)
let T(x, p) = (x thinks p)
let I = I (you, the person reading)
Az. = for all z
Ez. = there exists a z (Sorry aobut this, but I can’t type an upside-down E. Use context.)

Premises:

  1. Ax.(~E(x) -> ~Ey.(T(x, y)))
  2. T(I, ~E(I)) (for a lark)

Logic:
3) ~E(I) -> ~Ey.(T(I, y)) substituting I for x in 1
4) Ey.(T(I, y)) generalizing second I for ~E(y) in 2
5) E(I) modus tolens on 3, 4

In English:

  1. For anything(x), if it doesn’t exist, it is not the case that there is something(y) that it is thinking about. (Or, Things that don’t exist don’t have thoughts.)

  2. ‘I’ am thinking that I don’t exist.

  3. If ‘I’ don’t exist, it is not the case that there is something that ‘I’ am thinking about.

  4. There is something I am thinking about.

  5. I exist.

Have at.

111

In step 2, that should have been ‘generalizing second I for y in 2’. Sorry about that.

112

AAACK! That was supposed to be in step 4. (Sheesh.)

113

Dammit, I was right in the original post. I’m just going to back away now. (I need to do formalized logic more often, I’m getting sloppy…)

114

:smack: From the top…

Premises:

  1. Ax.(~E(x) -> ~Ey.(T(x, y)))
  2. T(I, ~E(I)) (for a lark)

Logic:
3) ~E(I) -> ~Ey.(T(I, y)) substituting I for x in 1
4) Ey.(T(I, y)) generalizing ~E(I) to y in 2
5) E(I) modus tolens on 3, 4

The logic was always good, anyway, but my justifications… :rolleyes:

115

posted by begbert2

If it cannot be thought of, and/or cannot become an object to awareness then it can’t be observed. If there is only one entity that is this I then this I can’t observe itself.

We are always talking about subject–object dualism which defines how “knowing” comes about. The distance between this subject and its objects is apparently an illusion. Once this distance is bridged you become the things you once merely knew. And finally you are something, although there is further transcendence to go.

It’s a mistake we all make and one we are trying to correct.

The I in dalovindj’s statement yields the lie.

The problem with the premise[s] is we don’t know who’s wondering. It is not the case that “** I **“ wonder. I’m the wondering no the wonderer. A verb, not a noun. The process no the processor. An object not a subject.

There is no one wondering.

It’s like the wondering is being observed by nothing, yet here it is. If you ask, “Does something exist?….that’s just more wondering. There’s no one to answer the question, and no one asked it.

I second that.

116

i must disagree with your premises. if you assume ~E(I), then premise 2) can’t be valid, in my opinion. that is, premise two should read:

  1. E(I) & T(I, ~E(I)

if you do not assume E(I), how can you assume T(I, ~E(I))?

117

Especially that it is. Still think we agree?

Well now we’re coming full circle.

118

ok, yeah, i was off a bit. it should’ve been:

  1. Ax.(~E(x)) -> ~(E(y) & T(y, ~E(y)))
  2. E(I) & T(I, ~E(I))

i remain unconvinced that T(I, ~E(I)) is possible, given ~E(I).

119

Whoa-boy! You’re assuming the negation of the conclusion of the proof?!? :eek:

Now look, that’s dirty pool. As it would be if I were to assume 2) E(I) & T(I, ~E(I)), which I most definitely don’t. That wouldn’t be any fun; it’s called 'begging the question. And I certainly don’t assume ~E(I) to be given. It’s what I’m trying to determine!!!

I don’t assume that I exist; I ‘assume’ that I think, and then I take the baby-step to get from there to existing.

Now, come on. All those of you who consider it axiomatic that you don’t exist, beyond the capability to consider alternatives, repeat after me: “I know I don’t exist. Therefore, I don’t exist”. There; you’re done: an ironclad proof. Don’t you feel better? :rolleyes:

120

please tell me how it is possible to assume that you think without first assuming that you exist in order to be able to think?