ABDUÇÃO - Lógica

Fonte: https://plato.stanford.edu/entries/abduction/

In the philosophical literature, the term “abduction” is used in two related but different senses. In both senses, the term refers to some form of explanatory reasoning. However, in the historically first sense, it refers to the place of explanatory reasoning in generating hypotheses, while in the sense in which it is used most frequently in the modern literature it refers to the place of explanatory reasoning in justifying hypotheses. In the latter sense, abduction is also often called “Inference to the Best Explanation.”

[Definição moderna: justificar hipóteses. Inferir a Melhor Explicação]

Most philosophers agree that abduction (in the sense of Inference to the Best Explanation) is a type of inference that is frequently employed, in some form or other, both in everyday and in scientific reasoning.

[Usada tanto no dia a dia quanto na própria ciência]

The type of inference exhibited here is called abduction or, somewhat more commonly nowadays, Inference to the Best Explanation.

Abduction is normally thought of as being one of three major types of inference, the other two being deduction and induction.

It is standard practice to group non-necessary inferences into inductive and abductive ones. Inductive inferences form a somewhat heterogeneous class, but for present purposes they may be characterized as those inferences that are based purely on statistical data, such as observed frequencies of occurrences of a particular feature in a given population.

The mere fact that an inference is based on statistical data is not enough to classify it as an inductive one. You may have observed many gray elephants and no non-gray ones, and infer from this that all elephants are gray, because that would provide the best explanation for why you have observed so many gray elephants and no non-gray ones. This would be an instance of an abductive inference. It suggests that the best way to distinguish between induction and abduction is this: both are ampliative, meaning that the conclusion goes beyond what is (logically) contained in the premises (which is why they are non-necessary inferences), but in abduction there is an implicit or explicit appeal to explanatory considerations, whereas in induction there is not; in induction, there is only an appeal to observed frequencies or statistics. (I emphasize “only,” because in abduction there may also be an appeal to frequencies or statistics, as the example about the elephants exhibits.)

[Não basta observar, tem que entender a causa do fenômeno.]

A noteworthy feature of abduction, which it shares with induction but not with deduction, is that it violates monotonicity, meaning that it may be possible to infer abductively certain conclusions from a subset of a set S of premises which cannot be inferred abductively from S as a whole.

[Não é monotônica, não apresenta monotonicidade. É possível concluir algo como verdadeiro/correto para um subconjunto que não é para todo o conjunto. Nem sempre SE A ENTÃO B, pode ser SE a1, a2, a3 ENTÃO B e A={a1, a2, a3, a4, a5}]

The type of inference exemplified in the cases described at the beginning of this entry will strike most as entirely familiar. Philosophers as well as psychologists tend to agree that abduction is frequently employed in everyday reasoning. Sometimes our reliance on abductive reasoning is quite obvious and explicit. But in some daily practices, it may be so routine and automatic that it easily goes unnoticed. 

[Conscientizar sobre a influência do Viés para achar a melhor explicação. Se o Viés se tornar explícito pode ser possível evitar descartar hipóteses válidas assim como perceber que quem tem explicações diferentes não está necessariamente errado.]

Similar remarks may apply to what some hold to be a further, possibly even more fundamental, role of abduction in linguistic practice, to wit, its role in determining what a speaker means by an utterance. Specifically, it has been argued that decoding utterances is a matter of inferring the best explanation of why someone said what he or she said in the context in which the utterance was made.

[ChatGPT responde sempre a The Best Explanation? Tenta com "boa intenção" mas é Indutivo pq se baseia em modelo de linguagem. Se contestado, "flexibiliza" pq não é "dogmático" e APRENDE.] 

[Me lembrou este artigo -> https://versant-pesquisadedoutorado.blogspot.com/2022/12/modeling-and-contextualizing-claims.html]

Abductive reasoning is not limited to everyday contexts. Quite the contrary: philosophers of science have argued that abduction is a cornerstone of scientific methodology...

Arguably, however, abduction plays its most notable philosophical role in epistemology and in the philosophy of science, where it is frequently invoked in objections to so-called underdetermination arguments. Underdetermination arguments generally start from the premise that a number of given hypotheses are empirically equivalent, which their authors take to mean that the evidence—indeed, any evidence we might ever come to possess—is unable to favor one of them over the others. From this, we are supposed to conclude that one can never be warranted in believing any particular one of the hypotheses.

Those responding then argue that even if some hypotheses make exactly the same predictions, one of them may still be a better explanation of the phenomena predicted. Thus, if explanatory considerations have a role in determining which inferences we are licensed to make—as according to defenders of abduction they have—then we might still be warranted in believing in the truth (or probable truth, or some such, depending—as will be seen below—on the version of abduction one assumes) of one of a number of hypotheses that all make the same predictions.

Its core idea is often said to be that explanatory considerations have confirmation-theoretic import, or that explanatory success is a (not necessarily unfailing) mark of truth. Clearly, however, these formulations are slogans at best, and it takes little effort to see that they can be cashed out in a great variety of prima facie plausible ways. Here we will consider a number of such possible explications, …

ABD1

Given evidence E and candidate explanations H1,…, Hn of E, infer the truth of that Hi which best explains E.

it presupposes the notions of candidate explanation and best explanation, neither of which has a straightforward interpretation.

Some think that abduction warrants an inference only to the probable truth of the best explanation, others that it warrants an inference only to the approximate truth of the best explanation, and still others that it warrants an inference only to the probable approximate truth.

For ABD1 takes as its premise only that some hypothesis is the best explanation of the evidence as compared to other hypotheses in a given set. Thus, if the rule is to be reliable, it must hold that, at least typically, the best explanation relative to the set of hypotheses that we consider would also come out as being best in comparison with any other hypotheses that we might have conceived (but for lack of time or ingenuity, or for some other reason, did not conceive).

[Melhor Resposta Possível do KG também considera que o KG é incompleto e por isso podem haver respostas que não fazem parte do KG ainda ....]

For given the hypotheses we have managed to come up with, we can always generate a set of hypotheses which jointly exhaust logical space. Suppose H1,…,Hn are the candidate explanations we have so far been able to conceive. Then simply define Hn+1 := ¬H1 ∧ … ∧ ¬Hn and add this new hypothesis as a further candidate explanation to the ones we already have. Obviously, the set {H1,…,Hn+1} is exhaustive, in that one of its elements must be true.

ABD2

Given evidence E and candidate explanations H1,…, Hn of E, infer the truth of that Hi which explains E best, provided Hi is satisfactory/good enough qua explanation.

Needless to say, ABD2 needs supplementing by a criterion for the satisfactoriness of explanations, or their being good enough, which, however, we are still lacking.

[A camada de confiança se encarregaria de aplicar as regras para identificar qual é a melhor dado o conjunto de respostas]

ABD3

Given evidence E and candidate explanations H1,…, Hn of E, if Hi explains E better than any of the other hypotheses, infer that Hi is closer to the truth than any of the other hypotheses.

In recent years, experimental psychologists have started paying attention to the role humans give to explanatory considerations in reasoning.

Even if it is true that we routinely rely on abductive reasoning, it may still be asked whether this practice is rational.

Hardly anyone nowadays would want to subscribe to a conception of truth that posits a necessary connection between explanatory force and truth—for instance, because it stipulates explanatory superiority to be necessary for truth. As a result, a priori defenses of abduction seem out of the question. Indeed, all defenses that have been given so far are of an empirical nature in that they appeal to data that supposedly support the claim that (in some form) abduction is a reliable rule of inference.

For instance, in considering possible confounding factors from which an experimental setup has to be shielded, scientists draw heavily on already accepted theories. The argument next calls attention to the apparent reliability of this methodology, which, after all, has yielded, and continues to yield, impressively accurate theories. In particular, by relying on this methodology, scientists have for some time now been able to find ever more instrumentally adequate theories. Boyd then argues that the reliability of scientific methodology is best explained by assuming that the theories on which it relies are at least approximately true. From this and from the fact that these theories were mostly arrived at by abductive reasoning, he concludes that abduction must be a reliable rule of inference.

[A Ciência não é dogmática]

For while Boyd concludes that the background theories on which scientific methodology relies are approximately true on the basis of an abductive step, the use of abduction itself does not guarantee the truth of his conclusion. After all, granting the use of abduction does nothing to ensure that the best explanation of the success of scientific methodology is the approximate truth of the relevant background theories. Thus, Psillos concludes, Boyd’s argument still stands.

Another suggestion about the connection between abduction and Bayesian reasoning—to be found in Okasha 2000, McGrew 2003, Lipton 2004 (Ch. 7), and Dellsén 2018—is that the explanatory considerations may serve as a heuristic to determine, even if only roughly, priors and likelihoods in cases in which we would otherwise be clueless and could do no better than guessing. This suggestion is sensitive to the well-recognized fact that we are not always able to assign a prior to every hypothesis of interest, or to say how probable a given piece of evidence is conditional on a given hypothesis.

Fonte: https://plato.stanford.edu/entries/abduction/peirce.html

Abduction (from Charles Sanders Peirce) denotes another type of non-deductive inference that is different from inductive type. But his concept is different from the modern one. Peirce abduction tries to generate theories that may later be assessed, or "is the process of forming explanatory hypotheses". Modern abduction is related to scientific inquiry concerning theories' assessment in the initial stage when explanatory hypotheses are conceived. 

There may be some satisfactory explanations for a phenomena, there might still be explanations better than others, and there might even be a unique best one. Later, deduction and induction can be used to derive testable consequences and to reach a verdict on the hypotheses.

In other words abduction can be explained "as a search strategy which leads us, for a given kind of scenario, in a reasonable time to a most promising explanatory conjecture which is then subject to further test” (Schurz 2008, 205). Search can discover explanatory hypothesis, creating a set of Best Possible Explanations. So at this point the hypothesis cannot be considered true or verified or confirmed, but must be a reason to suspect that each hypothesis is true and the selection criteria applied indicates which is a worthy candidate for further investigation.

[Existem algumas explicações (hipóteses) mas neste ponto mesmo que se encontre uma melhor que as outras, esta pode não ser necessariamente a Verdadeira em todos os casos. Best Possible Explanations seria um conjunto de explicações plausíveis (já filtra as que não se aplicam) que poderiam ser ordenadas por algum critério que justificasse a ordem de verificação.]