[alancalverd]

Difference between having a doubt, which is what distinguishes scientists from lemmings, and expressing a doubt, which can get you into serious trouble. So Galileo did the diplomatic thing and published a hypothetical discussion. Still got him into trouble, but less so than Bruno who was burned at the stake by a merciful and compassionate church for suggesting that distant stars might have orbiting planets.

[hamdani yusuf (OP)]

Having a doubt is adequate to be sure of our own existence, even when it's not expressed.

[Halc]

Having a doubt is adequate to be sure of our own existence

Being sure about something means the complete lack of doubt about it, so you defeat yourself with this self-contradictory statement.

It is very trivial to disprove a strong statement such as "X is necessarily true" by simply finding a counterexample, which I have done.  Far better to use the weaker form: "I presume X to be true" which just makes it a premise, not a necessary thing. Such a statement cannot be falsified by mere counterexample.

This topic is 60 posts in and you still don't seem to get that logic.

So my point was that the statement was presented as being necessarily true, and such a statement must be accompanied by a demonstration of that necessity, which it wasn't. He's not wording it as a premise, to be doubted or not at one's choice. Both of you present it as a necessity, and you still refuse to demonstrate that necessity despite multiple requests for that demonstration.

I think Descartes has demonstrated it pretty clearly. You are free to disagree, though.

That you think he has is irrelevant. He hasn't, and all you have shown is repeated assertions of same, not any kind of demonstration of necessity of it. As I said, I have shown a counterexample, which not only puts the necessity of the assertion in doubt, but actually disproves it.

I came up with a counterexample, so unless you can find a flaw in that counterexample, the necessity of your statement has been proven wrong.
If it's not necessarily true, then the statement is reduced to a mere premise, something that one is free to accept or decline as suits your fancy.

Are you referring to the number summation?

No, I'm talking about your assertion of the necessity of the existence of a doubter.


Here's another example:
Thinking is a process, and thus doubt is the result of a process. A process can take place despite the lack of existence of a 'thing' implementing the process.
So for instance, evolution is similarly a process, and a rabbit is an evolved creature, despite no rabbit having ever 'evolved'. There was never a creature that suddenly became more evolved (more rabbitty?) than it had been the day before. The process takes place between a rabbit and its ancestors. Now and then some creature had a descendant that was more rabbitty than the parent despite neither the creature nor the descendant actually doing any evolving.
Hence the process (evolution, thinking) does not necessarily require the existence of a specific thing implementing the process. But despite these counterexamples, you and your friend assert the impossibility of a process occurring without a unified 'thing' in which the process is implemented.
And yes, my first example demonstrates why what is naively referred to as "I" in the human language does not necessarily correspond to a temporally extended unified thing which would have otherwise have qualified as this thinker. But of course you just glaze over that because it demonstrates your position to be false, and hence must be discarded. That's how rationalization works. Answer comes first, then gather only evidence that supports it.


A thought experiment, closer to the point under consideration:
We do the Schrodinger's cat thing, except we stuff Halc in the box, legendary doubter of existence. The quantum event is measured and Halc is put into a superposition of being dead or being alive. The alive Halc is doubting his existence, which is thinking, which necessarily requires existence according to you. Schrodinger opens the box to find a dead Halc. It seems that the doubt was thinking being done by a nonexistent Halc (at least by some interpretations of QM), and since no valid interpretation can be falsified, the doubt is justified.
Descartes could not have considered such a situation since QM was unknown at the time, and it opened up a whole new arena of things to doubt, all of which were axiomatically true at the time and even presumed necessarily true. History was to demonstrate otherwise in coming centuries.

[hamdani yusuf (OP)]

Being sure about something means the complete lack of doubt about it, so you defeat yourself with this self-contradictory statement.

So you think you can doubt your own existence.

[hamdani yusuf (OP)]

It is very trivial to disprove a strong statement such as "X is necessarily true" by simply finding a counterexample, which I have done.  Far better to use the weaker form: "I presume X to be true" which just makes it a premise, not a necessary thing. Such a statement cannot be falsified by mere counterexample.

Do you conclude that nothing is necessarily true?

[hamdani yusuf (OP)]

Here's another example:
Thinking is a process, and thus doubt is the result of a process. A process can take place despite the lack of existence of a 'thing' implementing the process.
So for instance, evolution is similarly a process, and a rabbit is an evolved creature, despite no rabbit having ever 'evolved'. There was never a creature that suddenly became more evolved (more rabbitty?) than it had been the day before. The process takes place between a rabbit and its ancestors. Now and then some creature had a descendant that was more rabbitty than the parent despite neither the creature nor the descendant actually doing any evolving.

Rabbitness is not a well defined attribute. We can pick thousands of rabbits randomly from around the world. There is no consensus to pick the most representative of a rabbit among them.

[hamdani yusuf (OP)]

A thought experiment, closer to the point under consideration:
We do the Schrodinger's cat thing, except we stuff Halc in the box, legendary doubter of existence. The quantum event is measured and Halc is put into a superposition of being dead or being alive. The alive Halc is doubting his existence, which is thinking, which necessarily requires existence according to you. Schrodinger opens the box to find a dead Halc. It seems that the doubt was thinking being done by a nonexistent Halc (at least by some interpretations of QM), and since no valid interpretation can be falsified, the doubt is justified.
Descartes could not have considered such a situation since QM was unknown at the time, and it opened up a whole new arena of things to doubt, all of which were axiomatically true at the time and even presumed necessarily true. History was to demonstrate otherwise in coming centuries.

I find it weird that you trust QM more than your own existence. How well do you understand it?

[alancalverd]

So for instance, evolution is similarly a process, and a rabbit is an evolved creature, despite no rabbit having ever 'evolved'. There was never a creature that suddenly became more evolved (more rabbitty?) than it had been the day before. The process takes place between a rabbit and its ancestors. Now and then some creature had a descendant that was more rabbitty than the parent despite neither the creature nor the descendant actually doing any evolving.

Rather a lot of entangled selfcontradictions here. Evolution is an observation, not a conscious or even individual action. The fact that you don't look exactly like both of your parents (which is obviously impossible) is summarised by saying you have evolved from them. You can observe differentiation of species as random genetic mutations get filtered by environmental stress, and you can indeed define an aristotype of any species - it's the essence of judging dog breeding and country shows!

[Halc]

So you think you can doubt your own existence.

What I choose to believe or doubt is entirely irrelevant to the necessity of your assertion.

Do you conclude that nothing is necessarily true?

Also irrelevant, but since you asked, the laws of thought seem necessary, and for the reasons Alan gave in post 5. https://en.wikipedia.org/wiki/Law_of_thought#The_three_traditional_laws
They cannot be proven, but by definition, it seems that no falsification of them is possible either.

Rabbitness is not a well defined attribute.

Not claiming otherwise, but you must agree that any rabbit is more rabbity than the 480-million-year-ago fish from which it (and you) evolved. That didn't happen in one generation. It was a process. My point again with that counterexample (since both you as always, and Alan, missed it) was that a process (thought, evolution) doesn't necessitate a specific object implementing the process (thinker, evolver).

Alan attempts to actually address my evolution example, but Alan also seems to be reading-comprehension impaired. You've not found any fault at all with any of my counterexamples demonstrating your assertions to be wrong.

Rather a lot of entangled selfcontradictions here.

None identified I see. All I see are strawman claims of what you apparently thought my point was. I was agreeing with your contributions to this topic until now.

Evolution is an observation, not a conscious or even individual action.

I called it a process, never suggesting it to be a conscious or individual action.  As a matter of fact, it was my point that process need not occur in any individual processor, a counterexample to HY's assertion that it is necessarily otherwise. So you seem to be reinforcing my point rather than pointing out any 'self-contradiction'.

While we're at it, evolution isn't an observation. Our knowledge of it may be due to observation, but the process itself is not, nor does it require, observation.

The fact that you don't look exactly like both of your parents (which is obviously impossible) is summarised by saying you have evolved from them.

I didn't make any such summary, but a creature not looking identical to its immediate ancestors is definitely part of what makes it fit, an advantage that first made the Eukaryotes far more fit than their predecessors which tended to produce nearly identical copies when reproducing.

[alancalverd]

Our knowledge of it may be due to observation, but the process itself is not, nor does it require, observation.

But we have never (until very recently) observed the process, only the outcome. Darwin and his predecessors had no means of sequencing a genome, much less editing one to see what happens. So the word "evolution", which had indeed been used before Darwin, must denote an observation or at most a presumed process.

Happy to wear the Pedant Pendant on this one!

I didn't make any such summary,

nor did I credit it  to you! It's my own riposte to Creationists, and has slaughtered many such infidels.

[hamdani yusuf (OP)]

What I choose to believe or doubt is entirely irrelevant to the necessity of your assertion.

You are free to choose actions, but you are not free to choose the consequences.

Here's how our discussion went.

Having a doubt is adequate to be sure of our own existence, even when it's not expressed.

Being sure about something means the complete lack of doubt about it, so you defeat yourself with this self-contradictory statement.

So you think you can doubt your own existence.

The bolded term is meant for everything else, except our own existence at the time of doubting. We can't be sure about our own existence before nor after the doubting.