[발췌] Cambridge Pragmatism

• 출처: Cheryl Misak 지음. Cambridge Pragmatism: From Peirce and James to Ramsey and Wittgenstein. Oxford University Press, 2016. 구글도서.
• 관련 발췌: Charles S. Peirce. The Doctrine of Chances (1878).

OF WHICH:

PART 1. Cambridge Massachussetts

1. Peirce  (11)

  1.1 Introduction  (11)
  1.2 The Pragmatic Maxim: Meaning, Use, Practice  (12)
  1.3 Belief and Disposition  (17)
  1.4 Truth  (23)
  1.5 Experience: Mathematics, Metaphysics, Religion, and Morals  (31)
  1.6 Logic and Probability  (39)
  1.7 Regulative Assumptions and the Principle of Bivalence  (48)

2. James  (52)
  2.1 Introduction  (52)
  2.2 Psychology: Observation and Experience  (53)
  2.3 Truth and Usefulness  (60)
  2.4 Willing to Believe  (63)
  2.5 Religious Experience  (67)
  2.6 James on Common Sense  (73)

OF WHICH:

※ 발췌 (excerpt):

* * *

( ... ... ) In articulating Peirce's position, I will focus upon Illustration of the Logic of Science, ‘Prolegomena to an Apology for Pragmatism’, and his letters to Victoria Welby. In this material, one gets Peirce's pragmatic maxim, inquiry-centred account of truth, and formal logic--the existential graphs and their extension to modalities and intentions. These were the materials that were accessible in 1923 to Russell, Ramsey, and Wittgenstein.


1.2 The Pragmatic Maxim: Meaning, Use, Practice

The 1878 article ‘How to Make Our Ideas Clear’is one of the essays in Illustrations of the Logic of Science, and it contains the best-known, if not the most felicitous, statement of the pragmatic maxim. Peirce was not happy with his expression of the maxim in this paper ( ... ... )

The pragmatic maxim requires our beliefs, theories, and concepts to be linked to experience, practice, expectations, or consequences. ( ... ... )




( ... ... ) We shall see in the next section how much important the ‘normative sciences’ were for him.

A question arises as to how Peirce can distinguish truth-conductive experiences (or pieces of evidence) from misleading ones. The issue arises in every kind of inquiry, from science to ethics. His criterion for the truth-conductivity of an experience has been signaled already--experience that leads us to beliefs that work or gives us habits that enable us to successfully predict and act is the right kind, the kind that leads us to the truth. The question is one for every pragmatist, and it will be a theme that runs through the whole of this book.


1.6 Logic and Probability

Peirce thought of himself first and foremost as a logician. Indeed, that was the one intellectual community in which he was known and respected. The London mathematician and philosopher W. K. Clifford reportedly thought him to be the greatest living logician, and the only logician 'since Aristotle who has added to the subject something material'.[주]27  ( ... ... ) Peirce developed ( ... ) ; and made advances in the logic of statistical reasoning. The latter is especially important to understanding the influence he might have had on Ramsey. So is his definition of logic.

Peirce conceived of logic in an unusual way--a way that struck Ramsey as right. Logic is a 'normative science', along with ethics and aesthetics. [:]

• Aesthetics, the most abstract of the normal sciences, is to provide us with our ultimate aims. 
• Ethics explores the connection between our aims and our conduct. 
• Logic is the study of valid inference, and hence explores a particular kind of conduct--rational conduct. Logic is about finding habits of reasoning and inference that do not lead us astray. It tells us how to conduct in an inquiry aimed at truth. It is ‘the doctrine of truth, its nature and the manner in which it is to be discovered’ (W 3: 14, 1872).

From 1902 on, he had in mind to write a logic text, titled Minute Logic While it would have had formal material in it, it would have had at its center the study of inquiry aimed at the truth. He tells us in one prospectus:

Begin, if you will, by calling logic the theory of the conditions which determine reasoning to be secure ... Logic, then, is a theory. The end of any theory is to furnish a rational account of its object ... A theory directly aims at nothing but knowing. Maybe, if it be sound, it is likely, some day, to prove useful. Still, fairness forbids our making utility the criterion of the excellence of the theory.   [CP 2. 1, 1902]

( ... ... )

To see how logic is bound up with inquiry in Peirce's thought, we need a summary of the three kinds of reasoning he identifies: deduction, induction, and his own contribution, abduction. In his early work, in papers Ramsey had access to, Peirce calls abduction 'hypothesis'. It is fundamentally creative[주]30 or 'ampliative'. It goes beyond what is in the premises, unlike deduction, which explicates what is in the premises. Abduction is thus capable of importing new ideas into our body of knowledge. It takes the form:

The surprising fact, C, is observed;
But if A were true, C would be a matter of course.
Hence, there is reason to suspect that A is true.     [CP 5, 189, 1903]

Something very like this now gets called inference to the best explanation.[주]31  Peirce might well have been happy with this label, as he says that this mode of inference is 'the operation of adopting an explanatory hypothesis' (CP 5. 189, 1903).  He would not have been happy, however, with the modern idea that explanatory power is evidence for the belief's corresponding to reality. ( ... ... )

Peirce takes the first step in the scientific method to be abductive inference. [:]

• A hypothesis or a conjecture is identified that explains some surprising experience--some exception to what was expected. 
• Consequence are then deduced from this hypothesis and are tested by induction. 
• If the hypothesis passes the test of induction, then it is accepted--it is stable and believed until upset by a new and surprising experience. 

The scientific method thus proceed as follows: from abduction, to deduction, to induction. Peirce thinks that because abduction and induction both add to our knowledge, 'some logicians have confounded them'. But he clearly means to describe the two types of inference as separate stages of a tripartite process of scientific inquiry (W 3: 330, 1878).
( ... ... )

Whether or not Peirce being fair to Hume (I think he isn't), his point is novel and important. As I have argued elsewhere,[주]32  Peirce's account of abductive inference anticipated Nelson Goodman's Fact, Fiction, and Forecast in allowing us to see our way through Hume's problem by reframing it as a problem not for induction, but for hypothesis formation. ( ... ... )

Let us turn to Peirce's accunt of probability and statistical inference. He thinks that there is an objective and a subjective side to probability. We have already seen that in ‘The Fixation of Belief’, he makes reference to degrees of belief. He continues that talk in ‘The Doctrine of Chances’, also part of the Illustrations of the Logic of Science. He identifies the problem of probabilities thus:

The general problem of probabilities is, from a given state of facts, to determine the numerical probability of a possible fact. This is the same as to inquire how much the given facts are worth, considered as evidence to prove the possible fact. Thus the problem of probabilities is simply the general problem of logic.   [W 3: 278, 1878]

Peirce's question is to figure out how to weigh evidence.[주]33 or how to inquire into what the given facts are worth. His answer is that degrees of belief must line up with the facts:

Numbers one and zero are appropriated ... to marking these extreme of knowledge; while fractions having values intermediate between them indicate ... the degrees in which the evidence leans toward one or the other.    [W 3: 278, 1878]

He then applies the pragmatic maxim: ‘To get a clear idea of what we mean by probability, we have to consider what real and sensible difference there is between one degree of probability and another’. The difference is a matter of fact: 'in the long run, there is a real fact which corresponds to the idea of probability, and it is that a given mode of inference sometimes proves successful and sometimes not, and that in a ratio ultimately fixed’. An occurrence is more or less probable because, were an agent to perform indefinitely many inferences concluding that relatively similar events would obtain on the basis of relatively similar evidence, he would ultimately discover that this sort of inference tended definitely to a certain degree of success. In the long run, the 'fluctuations become less and less; and if we continue long enough, the ratio will approximate toward a fixed limit'. This might today be called an agency theory of probability, in which probability is a matter of what inferences are good for the agent who is intervening in the world. Probability is analyzed in terms of the reliability of an agent's habit of inference.[주]34

But in another signature move, Peirce wants to ensure that his concept is also objective. Probability is grounded in fact. He adopts a kind of frequency theory of probability, applied to the success of inferences. The frequency theory has it that probability is the limit of the relative frequency with which an event occurs. What we mean when we say that 'the probability that this coin will land heas is 0.5' is that, were we to toss the coin very many times, independently and under as identical conditions as are possibe, the percentage of times that the coin lands heads would converge upon 50.

A big problem for the frequency theory is how to make sense of the single case. Peirce puts it thus:

An individual inference must be either true or false, and can show no effect of probability; and, therefore, in reference to a single case considered in itself, probability can have no meaning. Yet if a man had to choose between drawing a card from a pack containing 25 red cards and a black one, or from a pack containing 25 black cards and a red one, and if the drawing of a red card were destined to transport him to eternal felicity, and that of a black one to consign to everlasting woe, it would be folly to deny that he ought to prefer the pack containing the larger portion of red cards, although, from the nature of risk, it could not be repeated.  [W 3: 282-3, 1878]

We need not even imagine such dire single case risks. The fact that we will all die, Peirce says, means that each of us will take only a finite number of risks and make only a finite number of inferences. Since the ‘very idea of probability and of reasoning rests on the assumption that this number is indefinitely great’, we are always facing a version of the single case problem.

Peirce's solution coheres perfectly with the view that the truth is what we would eventually come to, were we able to experiment into the definite future:

logicality inexorably requires that our interests shall not be limited. They must not stop at our own fate, but must embrace the whole community. This community, again, must not be limited, but must extend to all races of beings with whom we can come into immediate or mediate intellectual relation. It must reach, however vaguely, beyond this geological epoch, beyond all bounds. He who would not sacrifice his own soul to save the whole world, is, as it seems to me, illogical in all his inference, collectively. Logic is rooted in the social principle.     [W 3: 284, 1878]

Peirce immediately makes his solution to the single case problem palatable by saying that we need not actually engage in ‘the heroism of self-sacrifice’. The requirement is merely that each of us should ‘perceive that only that man's inferences who has it are really logical, and should consequently regard his own as being only so far valid as they would be accepted by the hero’.

We can extract two important points from this argument. [:]

One is about the structure of knowledge. Science, inquiry, and rationality involve getting our beliefs in line with experience, evidence, and reasons in an ongoing project. Logic or rational inquiry is rooted in a ‘social principle’, for investigation into what is true is not a private interest but an interest ‘as wide as the community can turn out to be’.  Rationality is social in nature because it requires more evidence than what is before an individual or even before a community. A rational inquirer tries to get as much evidence as she can. In our effort to understand reality ‘each of us is an insurance company’ (W 2: 270, 1869). We make bets that will pay out (or not) later. If ‘the whole utility of probability is to insure us in the long run’, then to be fully insured, we need to collect, evaluate, and scrutinize as much evidence as we can. The more evidence one takes in, the more one is likely to have successful actions. Of course, short-cuts will have to be taken, as it would be absurd for each individual to try to gather all the evidence for herself--inquiry is a community project. The linkage between degrees of belief and their working in action is that if you fix your degrees of belief according to the (frequentist) objective chances, and if you take in a lot of experience, you will be more successful than if you had gone in for some other method of fixing your degrees of belief. The bets you would make on this method ought to be made with a ‘great confidence’.

The other point is about the structure of value. As Scheffler (2013) argues, if we knew that human beings would become extinct once everyone currently alive died a natural death, then our own lives, contributions, and practices would diminish in value. While Scheffler is not writing about pragmatism, his insight is a fundamental insight of that tradition. The concept of knowledge, rationality, and value make sense only within ongoing (although we do not have to believe them infinitely ongoing) practices of inrquiring, justifying, acting, and living.

( ... ... )