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Induction and Deduction

tblood

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The construction of meaning in a system of signs - Abductive inference as semiotic exegesis/interpretation

If we replace the surprising fact by the incomprehensible behavior of a person, then an abductive inference may help us to construct an intentionalist explanation through motives (reasons) that makes the behavior intelligible. All intentionalist or functionalist explanations in psychotherapy thus become interpretable as hypothetical constructions with abduction as their modus operandi.

(1) Observation: Person A shows behavior V in context K, utters x, etc.
(2) Hypothetical rule: A behavior x in context K has the meaning/function (f).
(3) Case/conclusion: A's behavior V has the meaning (f) (is motivated by f).

If we consider the mechanism in the semiotic plane, a sign is introduced as an unexplained result to which, by way of the construction of an encoding rule, or the application of a familiar encoding rule, meaning is or can be assigned (contexts, frames, etc. being of significance, too). Abduction, as a cognitive operation, creates the framework which makes it possible to attribute a singular meaning to signs. The interpretation of signs -- as the schema shows -- is always abductive, or in other words: the fundamental constructive principle of all semiotic interpretation is the finding or inventing of a hypothesis (abduction), i.e. the act of semiotic understanding on the part of a hearer can consist only in the attribution of meaning through a -- his/her -- frame of reference (encoding rule). Therefore, abductive inference is the basic principle of all hermeneutical procedures.

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The construction of meaning in a semiotic system/system of signs - Abductive inference as the interpretation of signs, or as an intentionalist explanation

Peirce writes about abduction, that [...] It's only justification is that, if we are ever to understand things at all, it must be in that way." How do we proceed from seeing to knowing, from the affection of our senses to the description of our perception in languuage? Here, too, abductive procedures are at work: as soon as I describe my perception linguistically, I interpret non-verbal signs abductively and transform them into language in a rule-governed way. Against the background of abduction theory it is trivial that perceptual judgments are constructive in themselves, they are already interpretations. All perception is, therefore, in principle construction. Carrying out inferences, therefore, does not always involve conscious reflections before we reach our conclusions; frequently these inferential processes take place below our level of awareness.

Applying the theory of abduction to the brain brings out the precise logic of Maturana's theory of autopoiesis. For the observer, the brain thus becomes comprehensible as an autonomous organ of abduction which, under the control of internal "rules" (cognitive maps, memory) -- not fixed/determined by the external world -- neuronally encodes the stimuli (perturbations) impinging upon the sensory receptors (this would quite literally be "in-formare") and so generates information from those stimuli.

Abductive inferences are the kind of hypotheses that are logically invalid and must, therefore, be corroborated deductively (within conceptual systems and theoretical frameworks) as well as inductively, i.e., pragmatically, by experience. Knowledge becomes intelligible by way of its abductive incorporation into a coding system (semiotic system/system of signs) the logic of which forms the frame within which the facts (phenomena) acquire meaning by virtue of having become signs. As synthetic inferences are content-increasing only if they go beyond the information contained in the premises, and as the conclusion predicates of the subject something not available in the premises, our thinking cannot and must not remain merely deductive if we want to enlarge our knowledge. Furthermore, it is the central insight of the theory of abduction that there is no induction without a pre-existent hypothesis which has been inferred or constructed abductively. Thus the constructivist hypothesis is confirmed that knowing is a path emerging from walking, and that we can only enlarge our knowledge of the world by inventing hypotheses that prove to be viable in the process of searching for paths. The seeds of all kinds of ways of worldmaking are contained in abductive inference. In semiotic terms, an abduction functions as the incorporation of a sign into a coding system (minimal theories, hypotheses) the logic of which forms the frame within which the phenomena that have become signs acquire meaning. Abductive inference, in comparison with logical rationality, is para-logical, irrational. Still, it appears this mode of inference is the most relevant form of thinking at all.
 

reason

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Really, I don't think that there is any such thing as inductive or abductive reasoning, only deduction and guesses (people usually call these guesses inductions or abductions, but it only seems to be because the bias of unstated assumptions).
 

redacted

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Really, I don't think that there is any such thing as inductive or abductive reasoning, only deduction and guesses (people usually call these guesses inductions or abductions, but it only seems to be because the bias of unstated assumptions).

Would you say guesses are deductive as well? That's the point I was trying to make...
 

animenagai

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i haven't read the whole thread, so forgive me for my laziness.my definitions of induction and deduction all come from my 3 years in philosophy, so forgive me once again if my definitions differ from the general public.

in philosophy, deduction by definition are arguments that are guaranteed 100% true. not even 99%, 100%. such an argument would be like:

a. a triangle has 3 sides.

b this shape is a triangle.

therefore c. this shape has 3 sides.


i think it is evident that this has to be true. i don't believe that even with an eternity of research can we overturn this logic.


induction works like this:

a. most triangles have 3 sides.

b. this shape is a triangle.

therefore c. this shape has 3 sides.

since i said 'most', it is not guaranteed. that in philosophy makes it a inductive argument.

a common use of induction (the type that hume writes on) goes like this:

a. the sun has risen every day

b. tomorrow is another day

therefore c. tomorrow the sun will rise.

what hume argues is that just because it has happenned before, there is really no good reason for it to happen this next time. imagine a chicken who lives with a farmer. every morning, the farmer feeds it some grain. this has happnned everyday of the chicken's life. one morning, this clever chicken uses induction and assumes that it will be fed. however, this particular day, the farmer kills it and has it for tea. indeduction according to hume is not reliable at all.

i know i've gone off in a tangent but all i wanted to show was the unreliable nature of induction vs the fool proof nature of dedcution. they are really different. therefore when you say that induction is deduction with hidden premises, i disagree. even if you draw out all of the hidden premises, chances are, it is not deductive.
 

redacted

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Guesses aren't a kind of reasoning, so no. But we can deduce from guesses.

So what is the mechanism for coming up with guesses then? They just materialize out of nowhere?

Guesses are governed by rules, like anything else.

There may be many many factors that go into a guess (that we aren't consciously aware of), and my whole point is that you can label those factors as premises. In that sense, a guess is deductive as well.

If you didn't have enough factors to come up with a guess, you couldn't. Having enough factors is analogous to having enough premises to make a deductive conclusion.

Even probabilistic guesses can be thought of as deductive as long as you have a premise stating some threshold of probability needed to assume something.

See what I'm getting at?
 

nomadic

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induction works like this:

a. most triangles have 3 sides.

b. this shape is a triangle.

therefore c. this shape has 3 sides.

since i said 'most', it is not guaranteed. that in philosophy makes it a inductive argument.

a common use of induction (the type that hume writes on) goes like this:

a. the sun has risen every day

b. tomorrow is another day

therefore c. tomorrow the sun will rise.

well inductive reasoning has more to it than that. its also about hypothesis formulation

It can also be like this:

a. aid's molecule learns to block new proteins that seek to destroy it
b. every chemical reaction may be linked to a genetic sequence
c. instead of making new proteins to attack it, maybe we should attack the gene that allows it to adjust to new proteins

im just saying... doesn't seem like a fair depiction of the possibilities...
 

animenagai

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well inductive reasoning has more to it than that. its also about hypothesis formulation

It can also be like this:

a. aid's molecule learns to block new proteins that seek to destroy it
b. every chemical reaction may be linked to a genetic sequence
c. instead of making new proteins to attack it, maybe we should attack the gene that allows it to adjust to new proteins

im just saying... doesn't seem like a fair depiction of the possibilities...

sure. obviously i used a simple example to display the nature of induction, the point is just that no matter how good the inductive argument is, it is not deductive.
 

reason

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So what is the mechanism for coming up with guesses then? They just materialize out of nowhere?
There are reasons and then there are reasons.

When someone asks for the reason for an idea, they sometimes want a causal explanation. And there are such explanations which describe where guesses "come from", but these reasons do not entail the logical content of the guess. That is, guesses do not "materialise out of nowhere", but their logical content does.

Many people confuse these two kinds of reasons, and it is the chief error of so-called inductive logic. Our sense experiences have a noticable causal relationship with our ideas, and we can often recall sensory experiences which taught us something new. However, these experiences do not actually entail what we learn, and from that fact the various problems of induction arise. In other words, people were fudging the two types of reasons, and expecting causal reasons to double up as logical reasons. The confusion is, perhaps, understandable. The language of logic is rife with the metaphor of causation, and some people extend their similarities too far.

The psychological and logical issues ought to be kept distinct.
 

nomadic

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sure. obviously i used a simple example to display the nature of induction, the point is just that no matter how good the inductive argument is, it is not deductive.

yeah, and i firmly believe that nobel prizes are won with induction more often than deduction...

the entire reason some correlations nowadays are considered "deductive" was because of "inductive' problem solving for instance...

in the beginning of time, who thought that there was a correlation with space between molecules and their density? only after someone discovered it and proved it.
 

animenagai

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yeah, and i firmly believe that nobel prizes are won with induction more often than deduction...

the entire reason some correlations nowadays are considered "deductive" was because of "inductive' problem solving for instance...

in the beginning of time, who thought that there was a correlation with space between molecules and their density? only after someone discovered it and proved it.

yep, i can agree with that too. the difference though is that the term 'deductive reasoning' is very much a corrupted form of what it was. a lot of so called deductive reasoning is really just inductive, or even worse, abductive reasoning (inference to the best solution).

take genetics for example. the guy took plants, breeded and cross breeded them and noted down the characteristics passed on from the parent to the child. he then said 'given this information, the best explanation is the existence of genes'. that really isn't deductive reasoning at all, but it does have a place in the world. after all with deductive reasoning, 90% of the time you don't learn anything new. we just need to keep in mind the shortcomings of inductive and abductive reasoning. i mean an argument like

a. there's a noise on the roof

b. it could be elves

c. no one here can think of a better explanation

therefore d. elves caused the noise on the roof

is obviously both an inference to the best solution and absolutely bullshit. the beauty of a deductive argument is very much the rare guaranteed nature of the conclusion. it is not like deductive reasoning hasn't caused any breakthroughs either. 'i think therefore i am' is a deductive argument (as long as you understand it) and now the most famous words in philosophy. there's a place for all these argument forms in our society. the important thing in this thread though is understanding that they are different. i think it is safe to say that induction and deduction are very different things indeed.
 

reason

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Amusing note on induction.

Russell was very concerned with the problem of induction. According to Hume, the principle of induction is synthetic, and therefore, any attempt to justify it inductively would beg the question. Must the principle of induction be presupposed without a reason? If this is a problem, then induction is peculiar indeed.

Take the following inductive inference:

a is y, b is y, c is y |= every x is y

This inference can be improved, or made more "cogent" by adding premises, for example:

a is y, b is y, c is y, d is y |= every x is y

Again:

a is y, b is y, c is y, d is y, e is y |= every x is y

And so on.

So what is the perfect inductive inference? Which inductive inference would be the most cogent? Well, presumably it is the argument with infinitely many premises:

a is y, b is y, c is y, d is y, e is y, ... |= every x is y

But 'every x is y' is now equivalent to the premises, and this is no inductive inference, but deductive! Moreover, the premises and conclusion are equal, that is, they say the same thing by different methods. In other words, the inference does not just beg the question, but is circular! Apparently, inductive inferences become stronger as more and more of the conclusion is begged. That is, the more closely an inductive inference resembles a circular inference the better, and yet despite striving to beg the question, Russell thought it a problem, too.
 

nomadic

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Must the principle of induction be presupposed without a reason? If this is a problem, then induction is peculiar indeed.

i imagine inductive reasoning is about finding a conclusion that cannot be made with the current structure of available deductive reasoning.

i mean, if a=b, b=c, then a=c right? <--- deductive

if the packers beat the giants, and the giants beat the cowboys, then packers should beat the cowboys.

but what if the cowboys beat the packers?

then i'd imagine there would be many different explanations

deductive would say = this game was an aberration

inductive might say = there are many reasons why it could be

either could be right. but neither reason is as specific enough to explain exactly why.
 

animenagai

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i imagine inductive reasoning is about finding a conclusion that cannot be made with the current structure of available deductive reasoning.

i mean, if a=b, b=c, then a=c right? <--- deductive

if the packers beat the giants, and the giants beat the cowboys, then packers should beat the cowboys.

but what if the cowboys beat the packers?

then i'd imagine there would be many different explanations

deductive would say = this game was an aberration

inductive might say = there are many reasons why it could be

either could be right. but neither reason is as specific enough to explain exactly why.

there's an error in your example. beating someone is very different from being the same as. heck, it is not even a greater than statement. if you said packers > giants > cowboys, then packers must > cowboys. however, you said that they beat them, hence there is an inequality going on. what you put forth was an inductive argument from the start, so there is a natural margin for error.
 

nomadic

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there's an error in your example. beating someone is very different from being the same as. heck, it is not even a greater than statement. if you said packers > giants > cowboys, then packers must > cowboys. however, you said that they beat them, hence there is an inequality going on. what you put forth was an inductive argument from the start, so there is a natural margin for error.

ah. yes u are right.

thnx for pointing that out. i guess announcers on espn talk too authoritatively sometimes for my own liking lol
 

animenagai

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ah. yes u are right.

thnx for pointing that out. i guess announcers on espn talk too authoritatively sometimes for my own liking lol

LOL announcers on ESPN make bigger mistakes than that :p

'good tackle by al... JOHNSON!' good ole emmitt
 

redacted

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There are reasons and then there are reasons.

When someone asks for the reason for an idea, they sometimes want a causal explanation. And there are such explanations which describe where guesses "come from", but these reasons do not entail the logical content of the guess. That is, guesses do not "materialise out of nowhere", but their logical content does.

Many people confuse these two kinds of reasons, and it is the chief error of so-called inductive logic. Our sense experiences have a noticable causal relationship with our ideas, and we can often recall sensory experiences which taught us something new. However, these experiences do not actually entail what we learn, and from that fact the various problems of induction arise. In other words, people were fudging the two types of reasons, and expecting causal reasons to double up as logical reasons. The confusion is, perhaps, understandable. The language of logic is rife with the metaphor of causation, and some people extend their similarities too far.

The psychological and logical issues ought to be kept distinct.

Blah, I've had a hard time explaining myself here.

Different approach:
-Computers are only capable of deduction
-The brain is a computer
-Therefore the brain is only capable of deduction

The mind, however, is a shitty program on the computer of the brain. It can output logically invalid things. The label "induction" only means anything in the program. At a deeper level, our brains are just doing deductive analysis all the time (that's what computation is). We don't have access to most of what's happening in the brain (since our consciousness is just one of many programs). So when we make inferences, we think they're novel. But they're really the result of some deductive process in some other program in our brain being sent as input to our consciousness.

Did that make any sense?

I said it before this other way: induction is actually a form of deduction where some of the premises are hidden by the bounds of our consciousness.

Howabout this way:
a->b
a
therefore b

If we had a->b stored somewhere in our unconscious, and we came upon a, we would conclude b. We would call this induction. But it's really just deduction with hidden premises.
 

SillySapienne

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I'll give this a rudimentary go!!!

Deduction is the process of assimilating known categorical information into novel *analogous* situations/circumstances to thereby make/draw intelligible, or probable conclusions. When we deduce, we integrate the law of constants into different yet similar domains.

Induction is the process of discovering a new category, or a previously unknown, invisible string that connects and coheres previously assumed unrelated parts.

Intuition is an inductive cognitive process, whereas reasoning is a deductive pursuit.

And both processes are dependent on one and other and tend to foster each other.

Personally, I find the process of deduction boring. The process of induction, however, I find to be pretty fucking cool.

And, at least for me...

Induction ~ synthesis

Deduction ~ analysis
 

nomadic

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I'll give this a rudimentary go!!!

Deduction is the process of assimilating known categorical information into novel *analogous* situations/circumstances to thereby make/draw intelligible, or probable conclusions. When we deduce, we integrate the law of constants into different yet similar domains.

Induction is the process of discovering a new category, or a previously unknown, invisible string that connects and coheres previously assumed unrelated parts.

Intuition is an inductive cognitive process, whereas reasoning is a deductive pursuit.

And both processes are dependent on one and other and tend to foster each other.

Personally, I find the process of deduction boring. The process of induction, however, I find to be pretty fucking cool.

And, at least for me...

Induction ~ synthesis

Deduction ~ analysis


yeah. i agree with ur opinion about which one u like better, and i THINK thats a good explanation. i do need more deductive reasoning tho...

its all too wispy in my head for the precise definition to be written down.... lol
 

reason

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dissonance,

Think in terms of natural selection. What good would a brain be if it were a perfect deduction machine? Perhaps it would have some use, but would have a major disadvantage--all the right premises woud have to be "built in". Imagine that this kind of brain evolves, but some mistakes creep into the system i.e. occassionally the information copying processes make mistakes a create something novel (analogous to genetic mutations). Sometimes these ideas will be flawed, even hazardous, but from time to time they might actually be improvements, good ideas, and worth keeping. Eventually natural selection begins selecting for brains which make these "mistakes", and moreover, for cognitive apparatus which deal with and evaluate them.

Some billion years later, brains are systematically making "mistakes", and calling them inductions, abductions, or more accurately, good guesses.
 
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