Radical doubt
I'm not an expert but was it Decartes who approached philosophy, life, with complete doubt? Descartes, if I'm correct, wanted indubitable truths on which to base his philosophy.
''[I]Cogito ergo sum[/i]'' he said and thereupon laid the foundation of his philosophy. I think he reeled in God too as one who is benevolent - enough to subdue Descartes' demon.
I was thinking about how one would go about finding such a truth - beyond the reach of radical doubt - that defeats skepticism of even the worst/best kind.
Here's what I came up with. It's not that well-formed an idea but for a beginner like me I think it's a good start.
Let's doubt everything, all truths, knowledge itself.
That translates to : D = There are NO truths.
Now, D can be either true or false.
Suppose D is true.
That means there are NO truths but...
that means D too is a falsehood.
A contradiction D & ~D
So D is false which entails that: T = There are some truths.
So radical doubt is a self-refuting position. It's impossible that there are NO truths.
Therefore, there is at least one truth.
What that truth is I don't know. Is it Descartes' cogito ergo sum? May be or may be not. It does seem logical. To doubt my own existence would require me to exist, right?
Is it another truth we aren't aware of?
What about the statement T = there is at least one truth? This can't be doubted since its negation is a contradiction.
However, T, by itself, doesn't do much. It proves, beyond doubt, that there is at least one truth but doesn't say what that truth is.
Do any of you have any idea what that/those truth(s) is/are?
''[I]Cogito ergo sum[/i]'' he said and thereupon laid the foundation of his philosophy. I think he reeled in God too as one who is benevolent - enough to subdue Descartes' demon.
I was thinking about how one would go about finding such a truth - beyond the reach of radical doubt - that defeats skepticism of even the worst/best kind.
Here's what I came up with. It's not that well-formed an idea but for a beginner like me I think it's a good start.
Let's doubt everything, all truths, knowledge itself.
That translates to : D = There are NO truths.
Now, D can be either true or false.
Suppose D is true.
That means there are NO truths but...
that means D too is a falsehood.
A contradiction D & ~D
So D is false which entails that: T = There are some truths.
So radical doubt is a self-refuting position. It's impossible that there are NO truths.
Therefore, there is at least one truth.
What that truth is I don't know. Is it Descartes' cogito ergo sum? May be or may be not. It does seem logical. To doubt my own existence would require me to exist, right?
Is it another truth we aren't aware of?
What about the statement T = there is at least one truth? This can't be doubted since its negation is a contradiction.
However, T, by itself, doesn't do much. It proves, beyond doubt, that there is at least one truth but doesn't say what that truth is.
Do any of you have any idea what that/those truth(s) is/are?
Comments (55)
Doubt is overrated. We need not doubt without some reason to doubt.
Could you doubt that this post is in English? What would that entail?
No. Descartes was a methodological skeptic, not a philosophical skeptic. His approach was to scrutinize all claims to knowledge, not to argue that knowledge is impossible. In fact he was quite certain that we can and do have knowledge, given that we can trust God to not allow for global deception.
There"truth" goes even deeper than that. With a careful reading of this statement one might observe that, I think therefore I am. Quite interesting but also probably a ticket to the burning at the stake in Decartes' time.
No, that was Pyrrho of Elis. He's considered the first Greek sceptic. He met several wise men (gymnosophists, magi) in the east during his travels with Alexander the Great which inspired him to live a life free from doxa. As such, scepticism has connections with eastern philosophy. Ataraxia, the mental state advocated by sceptics, should be regarded in that way imho, as a meditative attitude. That ataraxia is central to scepticism is further outlined in book 1 of the "Outines of Pyrrhonism" by Sextus Empiricus:
"Scepticism is an ability, or mental attitude, which opposes appearances to judgements in any way whatsoever, with the result that, owing to the equipollence of the objects and reasons thus opposed, we are brought firstly to a state of mental suspense and next to a state of "unperturbedness" or quietude. Now we call it an "ability" not in any subtle sense, but simply in respect of its "being able." By "appearances" we now mean the objects of sense-perception, whence we contrast them with the objects of thought or "judgements." The phrase "in any way whatsoever" can be connected either with the word "ability," to make us take the word "ability," as we said, in its simple sense, or with the phrase "opposing appearances to judgements"; for inasmuch as we oppose these in a variety of ways – appearances to appearances, or judgements to judgements, or alternando appearances to judgements, -- in order to ensure the inclusion of all these antitheses we employ the phrase "in any way whatsoever." Or, again, we join "in any way whatsoever" to "appearances and judgements" in order that we may not have to inquire how the appearances appear or how the thought-objects are judged, but may take these terms in the simple sense. The phrase "opposed judgements" we do not employ in the sense of negations and affirmations only but simply as equivalent to "conflicting judgements." "Equipollence" we use of equality in respect of probability and improbability, to indicate that no one of the conflicting judgements takes precedence of any other as being more probable. "Suspense" is a state of mental rest owing to which we neither deny nor affirm anything. "Quietude" is an untroubled and tranquil condition of soul. And how quietude enters the soul along with suspension of judgement we shall explain in our chapter (XII.) "Concerning the End.""
-Sextus Empiricus, "Outlines of Pyrrhonism" book 1, ch.4
"[i]Our next subject will be the end of the Sceptic system. Now an "end" is "that for which all actions or reasonings are undertaken, while it exists for the sake of none"; or, otherwise, "the ultimate object of appentency." We assert still that the Sceptic's End is quietude in respect of matters of opinion and moderate feeling in respect of things unavoidable. For the skeptic, having set out to philosophize with the object of passing judgment on the sense impressions and ascertaining which of them are true and which false, so as to attain quietude thereby, found himself involved in contradictions of equal weight, and being unable to decide between them suspended judgment; and as he was thus in suspense there followed, as it happened, the state of quietude in respect of matters of opinion. For the man who opines that anything is by nature good or bad is for ever being disquieted: when he is without the things which he deems good he believes himself to be tormented by things naturally bad and he pursues after the things which are, as he thinks, good; which when he has obtained he keeps falling into still more perturbations because of his irrational and immoderate elation, and in his dread of a change of fortune he uses every endeavor to avoid losing the things which he deems good. On the other hand, the man who determines nothing as to what is naturally good or bad neither shuns nor pursues anything eagerly; and, in consequence, he is unperturbed.
The Sceptic, in fact, had the same experience which is said to have befallen the painter Apelles. Once, they say, when he was painting a horse and wished to represent in the painting the horse's foam, he was so unsuccessful that he gave up the attempt and flung at the picture the sponge on which he used to wipe the paints off his brush, and the mark of the sponge produced the effect of a horse's foam. So, too, the Sceptics were in hopes of gaining quietude by means of a decision regarding the disparity of the objects of sense and of thought, and being unable to effect this they suspended judgment; and they found that quietude, as if by chance, followed upon their suspense, even as a shadow follows its substance. We do not, however, suppose that the Sceptic is wholly untroubled; but we say that he is troubled by things unavoidable; for we grant that he is cold at times and thirsty, and suffers various affections of that kind. But even in these cases, whereas ordinary people are afflicted by two circumstances, -- namely, by the affections themselves and, in no less a degree, by the belief that these conditions are evil by nature, --the Sceptic, by his rejection of the added belief in the natural badness of all these conditions, escapes here too with less discomfort. Hence we say that, while in regard to matters of opinion the Sceptic's End is quietude, in regard to things unavoidable it is "moderate affection." But some notable Sceptics have added the further definition "suspension of judgment in investigations."[/i]"
-Ibid. ch.12
Skepticism is a problem for philosophy because there is no absolute certainty in it. How does one overcome it? Do we fall back on pragmatism or do we just ignore it?
I think this view was also held by Bertrand Russell and was the starting point for his logical construction of the world.
It is not so popular in philosophy today, and not on these forums either. Many people here prefer some dosage of "common sense" and Wittgenstein's view that legitimately doubting P requires some evidence against P or, alternatively, that our ordinary methods of verification are somehow exempt from criticism. I am not sure that I really understand these ideas.
PA
Maybe the problem is the notion of "absolute certainty", not scepticism.
I don't. I retooled to scepticism years ago.
We become sceptics and attain ataraxia. It's not particularly hard.
Evidence that the law of non-contradiction is dubious.
The problem with this method is when do you stop doubting? When is there enough certainty for something to be justified?
If I see a flower outside my window, then do I have enough justification to believe there is a flower there just by seeing it? Or do I need to perhaps approach it and touch it? Smell it too? Move it, and interact with it in different ways?
In other words, with the method of doubt, how do we decide when to stop doubting?
Quoting PossibleAaran
I tend to agree with the statement. If I doubt something, I must have grounds for doubting it. Though I have to admit, that if I am honest, I don't often behave that way in practice. The reason why I adopted belief in the proposition quoted is because I was suffering from generalised anxiety disorder, OCD and hypochondria back then - so I determined to establish a philosophical method for when to worry and when not to worry (worry being somewhat similar to doubt). So then I learned, using that, not to worry (or doubt) in the absence of evidence, but only in the series of worries/doubts that were troubling me.
If I am honest, I continued to doubt other things even in the absence of evidence. It has been quite a methodological means for me to determine what can go wrong, and what can be done if it does go wrong. For example, I typically and often do this in my work and business. I doubt whether the work is good enough, or I doubt whether X or Y will do the right thing with the paperwork I need them to do for me, etc. So there is a certain degree of hypocrisy for me in holding to that belief. On the one hand, it did help me overcome an anxiety condition, on the other, I still practice it in many aspects of my life, where it yields results. But on a theoretical level, I cannot distinguish between when it's right to practice doubting and when it's not.
Of course there are truths.
Facts are true, or they wouldn't be facts. What is a truth, if not something that's true?
There are lots of facts. Here's one:
If all dogs are mammals, and all mammals are animals, then all dogs are animals.
Of course there are lots of other facts too.
Michael Ossipoff
Where is the fact? It is simply a proposal (hence the proposition). You said "If". Suppose someone doesn't buy into your 'If".
You are confusing consensus on a proposal with some sort of an idea that you call a fact or truth.
It's more than a proposition. It's a true proposition. That makes it a fact.
The proposition says nothing about a case in which its premise isn't true. The proposition only says something about the case in which all dogs are mammals and all mammals are animals.
If you doubt that premise, that doesn't mean that you disagree with or challenge the if-then proposition.
Since the premise is the part that you challenged, I must assume that the consensus that you're referring to is consensus about the premise. See above.
Having said what I said above, I should quality that statement a bit, by quoting a standard definition:
As "implication" is standardly, 2-valued truth-functionally, defined, an implication proposition is true unless its premise is true and its conclusion is false. And so the mere falsity of its premise would be enough to make an implication proposition true, by the standard 2-valued truth-functional definition of implication.
I tell a story based on that definition, at the Logic and the Philosophy of Mathematics sub-forum at this website, in a thread entitled, "A guy goes into a jewel-store owned by a logician who never lies."
My metaphysics is about abstract facts, which could very well contain a lot of false premises. (I don't claim that anything exists). But I claim that, for those if-then propositions, the premise, if true, would always make the conclusion true. Therefore, those if-then propositions that I refer to can't not be true, even by the standard 2-valued truth-functional definition that I quoted above.
...so they're if-then facts.
Michael Ossipoff
Because you say so? Suppose sometime disagrees?
Quoting Michael Ossipoff
I just did.
Finding "facts" outside of philosophy class is actually quite difficult.
Personally, as I said in my previous reply in this thread, I find the method of doubt problematic.
Rich answered:
I didn't mean you couldn't disagree. Obviously you can disagree with anything that you want to. I merely meant that you can't validly, justifiably disagree with an if-then proposition based on a belief that its premise is false.
To get an idea regarding what you're talking about, i recommend that you re-read the post that you're "replying" to.
The falsity of an implication proposition's premise doesn't make the impiication-proposition false. In fact, by the standard 2-valued truth-functional definition of an implication, the falsity of an implication's premise makes the premise true.
But, even if you don't like that standard definition, the falsity of an implication's premise certainly doesn't make the implication false.
You're repeating your previous comments, without paying attention to the answer that was given.
Facts aren't at all difficult to find.
You call yourself "Rich". That's a fact. Maybe "Rich" is really your first name. That, too, is a fact.
Those are just 2 examples. There are many other uncontroversial facts.
Establishing the premises of implications might be difficult. For example, regarding the if-then facts on which my metaphysics is based, many or most of their premises may very well be false, because I don't make any claims about anything being real or existent.
(In fact, because "real" and "existent" are metaphysically undefined, any claim that something is or isn't "real" or "existent" is a claim using meaningless words.)
That in no way invalidates the if-then facts.
But your statement quoted above seems based on a misunderstanding of what "fact" means. You're probably just expressing, in another way, your suspicion about the truth of the premises of some if-then facts. I've answered that.
Michael Ossipoff
Of course I can.
Quoting Michael Ossipoff
IF there is disagreement with the premise THEN there will be disagreement with the conclusion (as there always is). One might as well forget about everything until there is concensus with the premise/stated belief. I would think this is pretty obvious.
Quoting Michael Ossipoff
Yes, when people agree, they will agree. It is not true or false, it is the nature of human beings. Agreement (consensus) is often restated as facts. Despite this, it remains a belief.
Quoting Michael Ossipoff
No one knows what Rich is. You can say something about it and I might agree, but suppose I'm a hacker and have nothing to do with the name Rich? All information is subject to ambiguity some more so than others. You form beliefs but it doesn't make it a fact.
The problem with most analysis of the nature of things is that people are in need such a hurry to reach conclusions that they don't even pause for a second to consider alternatives that would undermined their conclusions. This is no doubt a product of an educational system that encourages the idea of "pat answers". That is why I stopped going to college courses. It trains students that there are facts that can be spoon fed by higher authorities. Actually those are the worst sources for information.
You need to do more (or at least some) listening, and less expounding.
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I’d said:
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You replied:
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I didn’t say you couldn’t disagree. I merely said that you couldn’t validly and justifiably disagree.
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…because the truth of an if-then proposition doesn’t at all depend on the truth of its premise.
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(…except that, by the 2-valued truth-functional definition of implication, the falsity of an implication’s premise makes that implication true by definition.)
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Here’s a tip: Find out something about a subject before you expound on it.
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Yes, saying that to you is a waste of time.
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I’d said:
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You reply:
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First you confuse the implication with its premise. Now you confuse it with its conclusion
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So yes, if you disagree with an implication-proposition’ s premise then you can (but needn’t) also disagree with its conclusion.
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The falsity of both the premise and conclusion of an implication-proposition doesn’t imply the falsity of the implication-premise.
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In fact, by the standard 2-valued truth-functional definition of an implication-proposition, if is premise is false, and its conclusion is false, then the implication-proposition is (by definition) true.
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But, even if you don’t like that definition, the falsity of both the premise and the conclusion of an implication-proposition certainly doesn’t contradict that implication-proposition.
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As I said before, if an implication’s premise is false, then the implication is saying nothing whatsoever about the truth of its conclusion.
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Your belief in the falsity of an implication-proposition’s premise and/or conclusion in no way implies a belief in the falsity of the implication-proposition itself.
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You need to get it straight, regarding the difference between an implication-proposition, its premise and its conclusion.
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…or at least you need to get that straight before expounding about the subject.
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Actually no. If I believe that an implication’s premise is true, and you believe that its premise is false, then we could both agree that its conclusion is true. …even if we both believe that the implication itself is true (…and even if we both agree that the implication itself is false…and even if we disagree on whether the implication is true or false.).
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Remember that an implication whose premise is false says nothing whatsoever about the truth of its conclusion.
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…pretty obvious to you, and entirely wrong.
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Yes, if we don’t know if an implication’s premise is true, then (even if we assume that the implication itself is true), we don’t know if its conclusion is true.
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But not knowing if an implication’s premise is true doesn’t mean that we don’t know if the implication-proposition itself is true.
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Some implication-propositions can be shown to be timelessly true, without testing them by looking at their conclusion in every instance. Some would just be agreed by all to be true, without argument.
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For example, my metaphysics is about abstract if-then facts, and I don’t claim that all of their premises are true, or claim anything about the “reality” or “existence” (whatever that would mean) of the abstract facts or what they refer to.
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What if it can be shown by argument, or it’s otherwise agreed, that an implication-proposition is intrinsically, inevitably, timelessly true?
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Unless someone shows an instance of its premise being true and its conclusion being false, there’s no reason to doubt that demonstration or agreement. (…unless someone shows an error in the demonstration.)
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I’d said:
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You replied:
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…none of which has any bearing on this topic.
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And, contrary to what you seem to mean, there really are facts. But we’ve been over that.
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I’d said:
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You answered:
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Irrelevant. You call yourself “Rich”. As I said, that’s a fact.
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No, you call yourself “Rich”, by using it as your login-name, and signing your posts with “Rich”. That isn’t subject to ambiguity.
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Maybe each “Rich” post is really from a different person. Fine. Right now you’re signing your post “Rich”. Thereby, you un-ambiguously calling yourself “Rich”.
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If all dogs are mammals, and all mammals are animals, then all dogs are animals.
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That’s another fact that isn’t subject to ambiguity.
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I never said that all of your beliefs are facts.
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Exactly! That’s why you’ve got to check your conclusions before you post.
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Michael Ossipoff
What makes you think you didn't understand your declaration of final arbiter? I did. I fully understand that you believe you are in the position of greater understanding. Fine. I disagree.
If you want to argue about what is valid and what is true and all of those other arbitrary terms, there is a thread thrashing that out right now. Suffice to say, I don't recognize you as the final arbiter. That belief is your own.
You called me Rich. I never called myself anything. Check your facts.
And that's what your problem is: Your delusional belief in your understanding of a topic on which you're quite clueless.
Is this about fuzzy relativism?
You're so innocent of any exposure to the subject, that you think that the things I've told you are just one person's personal opinion.
It's alright do disagree. But it would be better to disagree after educating yourself on the subject a bit.
Actually, there's much in logic about which there's widespread and firm consensus.
Sorry, but it's not a subject for Rich to make up.
My message to you is just that you should educate yourself, at least a little, before you post.
As I said, I'm not the final arbiter. But you're befuddled, all confused about the differences between an implication, its premise, and its conclusion.
Though I'm not the final arbiter, you need to educate yourself, at least a little, before you expound.
You're using "Rich" as your log-in name.
I've wasted enough time replying to vain, delusional ignorance.
My participation in this conversation is concluded.
Michael Ossipoff
May I return the favor, which was my original point, but I believe I said it far more eloquently.
But doubt casts a shadow over everything - your assumptions AND your methods. It's great to think of philosophy as an investigation but what if our technique is wrong or our clues are faulty? What then?
Of course I may be charged of asking for a ridiculous amount of certainty. However, who decides on what degree of certainty is acceptable?
Let's first look at method viz. Logic/rationality. To evaluate rationality we use rationality itself. In other words we already assume rationality is the correct method when we put rationality under the lens. It's a vicious circle.
I've had discussions with others and some have said that to examine rationality with rationality isn't a vicious circle as it appears. Rationality vindicates itself through ways other than itself. For instance it makes predictions which are accurate. It works over a wide range of fields from children's lego blocks to advanced chemistry and physics. Therefore, one can say that rationality has universal application over space and time - rationality has proven itself.
That's why I've used logic to make the argument in my OP.
Come to assumptions and we don't have that degree of certainty as we had for rationality. We can't be sure of our assumptions. In fact philosophical arguments seem to be exactly about differing assumptions. The method - rationality - is universal but the premises/assumptions are not.
So, given the situation it seems we can't be sure of finding truths in the sense of indubitable ones that withstand any and all rational assaults. This is the problem I'm talking about. We can doubt ALL truths and still be completely rational.
Being a good detective requires one to continually assess our own assumptions and methods, right?
I change direction. I'm only interested in understanding nature. The more I look the better my skills.
The problem with logic is that you never go beyond where you are and the only skill that you are honing is restatement of what you already know. If you want to enhance your skills in life you have to go out there and experiment and do it. I don't look for certainty. I look for knowledge that allows me to grow.
I just proved it. Can you name one truth that you're 100% sure of?
Quoting Ying
But then this solution leads to arbitrariness - something that isn't rational, right? We come to a consensus on what degree of certainty is acceptable but that decision is arbitrary. Anyway, I'm with you on this one. I think radical doubt should be used instead of solved. Every time we think we've found something we should doubt its veracity.
Quoting Ying
Skeptical ataraxia. Ok
That's a very pragmatic and beautiful.
As I said in my reply to Ying, radical doubt should be used rather than solved because as a tool it serves to remind ourselves to check and recheck our beliefs and as a problem it's unsolvable.
Yes, doubt pushes us forward to discover more. We are all explorers.
Well the cogito is a pretty good candidate for indubitable truth, but the trouble is it doesn't necessarily connect to any other truths, it leaves you in a position where you have to preface every claim with "it seems to me that ..." - but of course we want to know whether is, not just seems.
As others have said, the process of doubt is usually limited, it depends on prior acceptance of some truth(s). To doubt, you need some truths as a lever. If you extend doubt infinitely, then you automatically limit yourself to the cogito, in fact to strict solipsism, and you stay there so long as you're infinitely extending your doubt.
So that said, the "indubitable" truths that we work with on a day-to-day basis are mostly simple, perceptual level truths, truths that are based on the animal level of perception that your ancestors used to survive and pass on their genes with. That's not a guarantee of absolute certainty, and they're always subject to correction, but they're the closest things we have to absolute certainty in the empirical realm.
I think a lot of it (particularly with Descartes methodology) is a confusion between the processes of ordinary knowledge-gathering and the processes of mathematical/logical thinking.
In ordinary knowledge-gathering, you're actually making discoveries, you're learning something new about the world, new information. But this has to mean that empirical knowledge is always provisional.
In maths and logic, on the other hand, with a complex or difficult problem, you feel subjectively like you're making a discovery, like you would in the everyday process of knowledge-gathering, but what you're discovering was already implicit in the axioms, etc., that you start out with, so you're not in fact discovering new information, just unfolding what was implicit. (It may be new information to you, but that novelty is strictly subjective.)
What this means is that the standard of certainty in maths and logic cannot be applied to empirical knowledge, except in the sense that in empirical knowledge-gathering, you are creating an internally-consistent projection or model of how the world is, that you then test against eventuating reality. There's mathematical certainty, deductive certainty, within the model and the implications for testing that you can draw from it. But you can never be certain that the model you're using is the right model for the occasion.
And that's where empirical doubt is always possible, and it's basically the putting side-by-side of two internally consistent models. IOW, an anomaly crops up in experience, which means that there must be something wrong with the model you've been assuming to be true up till now; so then you figure out some other possible model for the world, and match your two models against each other, and filter the right one out on the basis of homely, perceptual level truths (measurements, meter readings, etc.) that you are less doubtful about.
Quoting TheMadFool
I'll name two:
1. If all dogs are mammals, and all mammals are animals, then all dogs are animals.
2, A posting attributed to Mad Fool asked me, " Can you name one truth that you're 100% sure of?"
Michael Ossipoff
Anyway, thanks for your reply. I learned a lot from it.
Then you believe in demons. I don't share that belief of yours.
Aside from that, are you referring to the doubt, or the asserted certainty?
Asserted certainty:
I do claim that there are uncontroversial metaphysical statements.
...but I don't make as many assertions as you might think, because I make no claim that the complex system of inter-referring timeless abstract if-then facts about hypotheticals, that i refer to, is "real" or "existent". (...whatever those words would mean.)
Doubt:
How sure are you that words can accurately and completely describe all of Reality?
If you can't say for sure that that's true, then any claim about all of Reality is questionable.
In any case, I'm not interested in debating or convincing anyone about the limits of discussion or description. I'd rather just discuss metaphysics, which is agreed, by most, to be discussable.
Michael Ossipoff
That's what I mean. Radical doubt is, must be, painful to philosophers because it undermines everything, from their axioms to their logic.
I think it's right to say that Descartes was looking for indubitable truths to serve as foundations from which he could infer anything else he was going to believe. He begins the search by considering his cognitions in general and, in particular, his sensory experiences. He tries to locate cognitions that are self-certifying. An explication of "self-certifying" is best found by illustration. Consider the practice of gazing into a crystal ball in order to contact the dead. The gazer comes to form various beliefs about what the dead are saying. It is possible to ask why we should take what the gazer says at all seriously. Why should we think that what he says is true? He will likely retreat back to the claim that his crystal ball allows him to contact the dead, but we will immediately wonder why we should take [I]this[/I] at all seriously. Why should we think that his crystal ball is reliable about these things? If we cannot find any answer to that question, there is a sense in which we will fail to assure ourselves that what the gazer says is true. That is, there will be a "why" question which he simply cannot answer.
All of these same issues arise for any and every method of belief formation. For example, I might answer a why question about my belief that there is a laptop in front of me by saying that I can see one, but this will lead to the question of why I should take sense perception to be reliable. I read Descartes as noticing this fact, that someone who is genuinely curious about the truth of their beliefs in general will raise why questions about any and every such belief. He seeks a way out of it - to satisfy his curiosity about the truth of his beliefs. To that end, he looks for beliefs about which a further why question makes no sense. He then tries to build the rest of his philosophy on top of those beliefs. His criterion for foundations ends up being clarity and distinctness. He thinks that when something is, in some sense, clear and distinct, there is no further question it makes sense to ask about why it should be accepted. He [I]also[/I] thought that propositions that were clear and distinct were absolutely certain, but we should note that whether or not clear and distinct propositions are such that no further why question makes sense about them, and whether or not they are absolutely certain are logically two completely different matters.
Many people think something like the following about Descartes. Descartes is lead into solipsism because he requires absolute certainty for his beliefs. If you don't require absolute certainty, then you can escape and believe everything that you normally do. Doubt is thus just a silly game of demanding certainty when it isn't needed. It is true that Descartes pursues absolute certainty in the Meditations. His foundations are absolutely certain, and he insists only on deductive inference which would preserve certainty. But it isn't true that just by abandoning that standard you can avoid the issues Descartes gets himself into. Suppose that we relax the standard of certainty to probability. We could then, in principle, allow merely probable foundations and probable inferences. We are still limited, however, to propositions such that no further why question makes sense. Philosophers who have relaxed the standard seem to me to have failed far worse than Descartes ever did. They either fail to recognize that intelligible "why" questions can still be raised about their foundations or they simply don't see the regress of why questions; they only see certainty, and dismiss Descartes for being obsessed with certainty.
From this perspective, consider Gurugeorge's Model Building ideas:
Quoting gurugeorge
How does a model get "tested against reality"?
Quoting gurugeorge
These ideas obviously assume that sense perception is reliable, and it is painfully easy to ask, why think that sense perception is reliable? And Gurugeorge seemingly has no answer to this question. The model building idea strikes me as very similar to Falsificationism, and I am attracted to that doctrine, but it has to be propped up by the claim that sensory experiences yield beliefs about which no further why question can be raised, and (since deduction is needed to deduce that a model is false given certain experiences) the claim that the rules of deductive inference have that status too. There may be ways to make these claims stick, but to do so one would have to employ either Descartes' idea of clarity and distinctness, or something which does the same job of answering that final why question. But those who say that Descartes' was just obsessed with certainty (perhaps guru doesn't hold this), never give such accounts. This is why I think they fail even more than Descartes did.
Now, it might be that [I]part of the model[/I] we are building is the assumption that sense perception and deduction are reliable, but if it is, what sense does it make to say that the model itself is tested by appeal to sense experience? To test a model which contains the theory that sense perception and deduction are reliable by appeal to sense perception and deduction is clearly question begging. Thus, these ideas about models always leave one with an unanswered "why" question about the key assumptions of the model. It isn't just that the assumptions aren't absolutely certain. Its worse than that. Its that no reason at all has been given to think the assumptions are true, not even a fallible or probable one.
Hence, construed as an attempt to solve the problem Descartes tried to solve, the model building ideas are a failure. If, however, the model building ideas aren't an attempted solution to that problem, I admit that I have no real idea how to understand them.
I should apologize to for picking on his post as an illustration. I wanted some way to make the Cartesian perspective clear by contrasting it with some other ideas. His post was the most well thought out and lucid of those that seemed appropriate for this purpose.
Best
PA
Great post! All I'll say here is that this is the nub of it: the only reason one gets so much as the idea that there's an anomaly (that casts doubt on one's model) in the first place, is because one is already relying on sense perception as valid enough to tell you that there's an anomaly; therefore, unless one is given reason to suppose otherwise, the subsequent model-testing sense-perceptions can have at least the same level of reliability. (And the "reasons to suppose otherwise" usually involve some break in the conditions for normal perception, with the possibility of correcting perception being already priorly accepted.)
IOW, if you think there's an anomaly at all, that information comes to you from sense perception, therefore (unless there's good reason to suppose otherwise - that's where the burden of proof lies) whatever perceptions you use to test your revised conception of reality must be on exactly the same level of reliability as the perceptions that gave you the very idea that there was an anomaly in the first place. The more certain you are that there was an anomaly, the more certain you must be that sense perception is at least in principle reliable enough to resolve the anomaly.
Going back to the arguments from illusion (and the gradual progression of Cartesian doubts in the course of the Meditations): the only reason why you think you were subject to an illusion (or why Descartes noticed he'd been in error about various things) is because of some corrective perception that reveals that your previous perception was an illusion. Therefore you're already implicitly allowing the validity of at least some sense perceptions: the corrective sense perceptions at least must be valid, for the illusion to be genuinely an illusion. Therefore you can't use the argument from illusion to globally doubt the validity of sense perception on the basis that sometimes you're subject to illusion.
Thanks for the reply guru. It seems we are slowly isolating the key disagreements between us. Here is one of them. You think that what Descartes does is something like this. He first notices that he has sometimes been mistaken. From this fact he extrapolates that he might be mistaken in any given instance, and that is why he suspends judgement prior to finding his proof of God's existence and such. If this were how he was thinking, then I'd say you would be right that to get this started, he has to take fore-granted that at least some of his sensory experiences are veridical. It seems right to me to say that he can't really do that unless he is already assuming the reliability of sense perception, and so that assumption would be a presupposition of the possibility of his doubting it. A remarkable transcendental argument against scepticism!
My reply would be that even if Descartes did proceed in the way you think, he need not have done so. Descartes need not assume that sometimes he is mistaken, in order to ask "why believe that sense perception is reliable?". He can simply ask it, can he not? Of course, he cannot sensibly ask it if he is also [i]assuming that sense perception is never mistaken or if he is assuming that sense perception is reliable[/I]. But he need not assume that. He can simply raise, relentlessly, with respect to every opinion he has, "why believe that?", until he reaches some beliefs for which this question cannot meaningfully be posed.
But, given your initial remarks about "getting the idea that there is an anomaly" in one's model, perhaps you think that for some reason Descartes cannot sensibly raise this question about the reliability of sense perception. It would be great if that were so, but how could it be?
Best
PA
I'd said:
You replied:
Quoting TheMadFool
But I was just referring to doubt about the controversial claim that all of Reality is discussable and describable.
I wouldn't say that logic is in doubt.
I claim that uncontroversial things can be said about metaphysics, and that much about what is, is unontroversially discussable, describable. That discussable, describable domain of what is (other than the physical sciences), I refer to as metaphysics.
But sure, all assumptions should be subject to question, and radical doubt, skepticism, is the right approach to philosophy.
For example, I suggest that people be skeptical about Materialism's big brute-fact.
Michael Ossipoff
No, of course he can ask it. But the short answer to the question "Why believe that sense perception is reliable?" is because it is in fact reliable.
And you can show that sense perception is in fact reliable because you can distinguish reliable perceptions from unreliable ones, and show that we have more reliable ones than unreliable ones: which means that sense perception is reliable. It's not absolutely guaranteed to give a nugget of truth every time, but it sometimes does and sometimes doesn't, and the fact that it mostly does is the very meaning of "reliable."
Again, it's the two concepts together that apply to reality, not just the one. If perception always gave guaranteed nuggets of truth, we wouldn't have the concept reliable, because we wouldn't have the concept unreliable, there would be no contrast, so we wouldn't notice, so the question wouldn't even come up.
The longer answer would involve evolutionary biology, anatomy, neurobiology, etc. And it would also involve looking at perceptions in the context of desires and expectations (whether they're fulfilled or not) - perception (for animals and us) is a phase of action in service of desire, and under expectations set by models as aforesaid. This would be connected with pragmatism, but I think pragmatism goes too far in tying truth connections simply to fulfillments. We are talking about truth, which is to say we are ultimately talking about the models/projections of how reality is, and using perceptions to filter the model. But the fact that using our perceptions gets us what we want is definitely tied in with what we mean by the reliability of perception: if we were baulked at every turn by following our perceptions, and ended up starving in a ditch, we wouldn't think much of perception.
(Now in all the above, I can sense you champing at the bit: you no doubt want to say, "But aren't sense perceptions being used in the very process of checking out whether sense perceptions are reliable?" This seems to be homing in on our disagreement even more: somehow, you think this is circular. But why?)
Btw, I can't resist it: if Descartes relentlessly asks "why?" then ultimately he's in the position of the child relentlessly asking "why?" in the comedian Louis CK's skit, and his intelocutor is entitled to lose patience with him at some point: "WHY? Aw fuck you, eat your french fries you little shit, goddamit." :D
https://www.bing.com/videos/search?q=louis+ck+why&view=detail&mid=9D4912E6BB08967131D39D4912E6BB08967131D3&FORM=VIRE
We can start by clearly differentiating belief from truth. Doubt pairs with belief, not truth.
One way of viewing scepticism is as a failure of nerve. The sceptic does not have the courage to commit.
Why?
Quoting Banno
Because there's no assurance that an assumption is right.
But it was just a comment, not an assertion, and it isn't something that I'd argue or debate.
I don't mean or want to tell others what to believe or what their attitude should be. So, if you don't think that your assumptions are subject to question, then I have no argument with, or criticism of, that.
Michael Ossipoff
Nor an assurance that it is wrong.
So why is it rational to doubt without reason, yet not to believe without reason?
Quoting Banno
Because when you admit to yourself that you don't have reason to believe something, then, by definition, you have doubt about it.
Michael Ossipoff
Then when you admit to yourself that you don't have reason to doubt something, then, by definition, you have belief in it.
Yes.
If you don't have reason to doubt it, that's because there's reason to believe it's true, and no reason to believe that it isn't true..
Or maybe you don't care about the proposition (whatever it might be), or have enough interest in it to know or care whether you doubt it or believe it.
But then you don't believe it, and, by definition you doubt it, even if you completely-disinterestedly doubt it.
Michael Ossipoff
Excellent stuff. I was tempted by this thought, and I did write a response explaining why I thought the argument was circular, but I don't think that's right after all. Your argument never uses the premise "sense perception is reliable" and so it isn't logically circular. I'm not sure that the argument is precise enough for me to disagree at this stage.
Quoting gurugeorge
How, exactly, can you distinguish veridical sense perceptions from non-veridical ones? And how can you show that we have more of the former than the latter?
This is the crux of it. If you can do that, then you have an answer to those pesky "why" questions.
Quoting gurugeorge
My old supervisor criticized my conception of skepticism for being "childish". I agree that there is a parallel between the child's constant questioning and the sceptical one. But I don't see why that makes the sceptical questioning objectionable. It isn't as though if children do P, then necessarily P isn't sensible.
Quoting Banno
The word "rational" is vague. I think a philosophical tradition that starts in Socrates and is carried through by various people to Descartes and - in some places - to Russell, defines rational belief as belief for which one has good reasons to hold. I don't think that is the "ordinary" meaning if there even is such a thing as that - I doubt it. But it is a good thing to have reasons for the things you believe and so good to strive to have them wherever possible.
The underlying assumption here is that belief requires justification. Why should it?
Count them. Seriously, just count them. Think of all the times when you've proceeded as if your sense perceptions have been correct, and your desires and expectations have been fulfilled by proceeding on the assumption that they're correct, versus the times you misperceived. You get up in the morning, you see what looks like a toothbrush, you pick it up and find you can brush your teeth with it. You reach for what looks like a door handle and find you can use it to open the door and get out of the house. You go to the train station, you step into what looks like a train and you find it's taken you to what looks like your place of work, which look like it has your workstation, where indeed the work is as you remember leaving it, etc., etc., etc. Maybe on the way home you encounter a situation like this:-
"I thought I saw a banker's clerk descending from a bus,
I looked again and saw it was a hippopotamus."
So there you have a whole slew of desires and expectations fulfilled by taking sense perceptions as veridical, and you have one misperception, one expectation baulked. The ratio I'd say is par for the course for the average day.
What else are you to conclude other than that sense perceptions are reliable? What else would reliability consist in, other than ... this sort of thing?
Is it logically possible that any segment of that sequence, or the whole sequence, might be systematically mistaken? Sure, but give a reason for it - until there's a reason to take seriously the idea that there's been systematic, thoroughgoing erroneous perception, then the hypothesis of systematic error is (as I've insisted elsewhere) mere idle imagination.
But even then, you'll always be juxtaposing correct perceptions against erroneous perceptions, even then correct perceptions still have to be possible in order to demonstrate that the whole sequence of perceptions above was erroneous. And that's because perception does that job: that's the burden of empiricism. Perceptions are truth-makers for propositions, that's the place they have in the economy of thought, and we have no other thing to take their place, certainly not schmerception (which is the truncated, presuppositionless way of looking at perception).
Quoting PossibleAaran
It's really more that the sceptic or the endless why-questioner isn't quite getting the game. "Why" questions have a limited ambit, always, they're delimited in a given universe of discourse, against a background in which some things are accepted as true. The extrapolation and extension is basically just continually moving the goalposts.
But we have to be careful here, because sometimes (e.g. a careful detective or journalist, or indeed a scientist or philosopher) pursuing questions a layer or two deeper than the original will discover something useful or interesting. (In this connection, see this wonderful Richard Feynman clip.) But that - knowing when to pursue a "why" question and when to drop it - is what makes inquiry partly an art and a game as well as a science - and partly a matter of judgement arising from long experience with particular fields.
This wasn't quite what I wanted. I understand that you think that one can use a track-record argument for the claim that sense perception is reliable. Sense perception got things right on occasions X, Y, Z, N, N+1... therefore sense perception is reliable. My question is, why believe, in any particular case, that sense perception got it right? I look into my bathroom and form the belief that there is a toothbrush on the sink. Why should I believe that there is? Remember, at this point we haven't established that sense perception is reliable, so we cannot appeal to that. Why, then, should I take it that sense perception is getting things right in this particular instance if I can't take it to be reliable yet? If the track record argument works, there must be some reason to believe its premises.
Quoting gurugeorge
I think that most sceptics knew perfectly well that they weren't playing the usual 'game' that is played in ordinary life. I don't think that Descartes was foolish enough to think that in ordinary life we pursue why questions all the way through. He even points this out himself in the Meditations. He saw that ordinary discourse involves taking many things for-granted. But his philosophy wasn't a description of discourse in London. It was an attempt to answer all of those why questions that aren't ordinarily answered. In doing this he recognizes that he's pursuing matters much further than they are usually pursued, but he has goals which he thinks are best achieved by doing this.
Yeah, I know it's kind of a boring answer. :)
Quoting PossibleAaran
There's no reason to believe it in any particular case, not by "reading off" from the perception (or even schmerception) in isolation. The perception's validity isn't given alongside the givenness of the perception.
But that's not a problem, because the reason to believe (trust in) the validity of any random given instance of perception comes from trust in the general series, which includes also the possiblity of occasional error. It seems kind of paradoxical, but it really isn't. We aren't guaranteed the validity of any given perception, taken in isolation, but we have a reasonable degree of proven confidence in the series as a whole, which means that the given perception is likely to be valid, but may occasionally not be.
It would be a problem if we were in the position of having to "read off" any given perception's validity from the perception itself in order to have knowledge. But we aren't, so it isn't.
Quoting PossibleAaran
You should believe it's a toothbrush because you're having a toothbrush-like perception, that's good enough reason to TRUST that you'll be able to brush your teeth with the damn thing.
Now that trust may turn out to have been misplaced (maybe it's an alien spaceship), but we know it's highly unlikely to have been misplaced (the chances of it being an alien spaceship, or any of an infinity of other logically possible things, including your hallucination as a brain in a vat, or whatever, is vanishingly tiny, and would require strong proof to counterbalance the chain of expectations-fulfilled that we've gotten by going along with perception as generally valid).
Quoting PossibleAaran
You can't take any given perception in isolation to be reliable, its reliability is something that can only be validated subsequently as part of a linked network of expectations fulfilled (so long as you're using perceptions as a guide to reality, in order to fulfil those expectations).
But the expectations' fulfillments are themselves things perceived, after all, so what else do you have to go on?
IOW, it's not a bug, but a feature. ("It" here being the lack of one-to-one guaranteed intrinsic relationship between a perception and its validity, that's somehow given along with givenness of the perception itself.)
Quoting PossibleAaran
Yes, and that's been a valuable exercise, but the fact that it hasn't led anywhere is what's instructive.