Logic and Conversation

Grice, Herbert P. “Logic and conversation.” In Speech acts, pp. 41-58. Brill, 1975.

Background and Motivation

There are, or appear to be, divergences in meaning between formal devices and their analogs or counterparts in natural language.

• formal devices: , , , , , , .
• their natural language analogs or counterparts: , , , , , , .

Those who concede the existence of such divergences adhere to one of the following groups: formalist group, and informalist group.

An outline of a characteristic formalist position:
The formal devices have a decisive advantage over their natural counterparts: For it will be possible, in terms of the formal devices, to construct a system of very general formulas, a considerable number of which can be regarded as, or closely related to, patterns of inferences the expression of which involves some or all of the devices. Such system may consist of

• a certain set of simple formulas that must be acceptable if the devices have the meaning that has been assigned to them, and
• an indefinite number of less obviously acceptable formulas, each of which can be shown to be acceptable if the members of the original set are acceptable.

Thus, there exists a way of handling dubiously acceptable patterns of inference, and a better way if we can apply a decision procedure.

Furthermore, the possession by the natural language counterparts of those elements in their meaning, which they do not share with the corresponding formal devices, is to be regarded as an imperfection of natural languages. The presence of these elements makes the precise definition of the concepts, in which they appear, impossible. In addition, some statements involving them cannot be assigned a definite truth value in some cases. We cannot be certain that non of these natural language expressions is metaphysically “loaded”.

For these reasons, these natural language expressions cannot be regarded as finally acceptable, nor fully intelligible.

A proper way out is to conceive and construct an ideal language, incorporating the formal devices, the sentences of which will be clear, determinate in truth value, and certifiably free from metaphysical implications.

Assumptions of the philosophical demand for an ideal language:

• The primary yardstick by which to judge the adequacy of a language is its ability to serve the needs of science.
• An expression cannot be guaranteed as fully intelligible unless an explication or analysis of its meaning has been provided.
• Every explication or analysis must take the form of a precise definition that is the expression/assertion of a logical equivalence.

There must be a place for an unsimplified and unsystematic logic of the natural counterparts of these formal devices, aided and guided by the simplified logic of the formal devices, but cannot be substituted by it.

Rules that hold for a formal device may not hold for its natural counterpart.

This paper aims to assert that

• the common assumption of the existence of the divergences is wrong, and
• this incorrect assumption arises from an inadequate attention to the nature and importance of the conditions which govern conversation.

Implicature (含意)

Definition: something the speaker suggests or implies within an utterance, while not literally expressed.

Example 1: He is in the grip of a vice.
Given the knowledge of English language, but no knowledge of the circumstance of the utterance, one would know that the speaker had said about a particular male person or animal , that at the time of the utterance, either

• was unable to rid himself of a certain kind of bad character trait, or
• some part of ’s person was caught in a certain kind of tool.

In order to fully identify what the speaker had said, oen would need to know

• the identity of
• the time of utterance
• the meaning
  on the particular occasion of utterance of the phrase .

Example 2:

1. He is an Englishman; he is, therefore, brave.
   vs.

2. He is an Englishman. He is brave.

3. Being the case that his being brave is a consequence of his being an Englishman.

4. The speaker do not want to say that he/she has said that it follows from his being an Englishman that he is brave, though he/she has certainly indicated, and so implicated, that this is the case.

In some cases the conventional meaning of the words used will determine what is implicated, besides helping to determine what is said.

Conversational Implicature (会话含意)

People’s talk exchanges are characteristically cooperative efforts to some degree, and each participant recognizes in them, to some extent, a common purpose or set of purposes, or at least a mutually accepted direction, which may be either fixed from the start (e.g., by an initial proposal of a question for discussion), or evolve during the talk exchange. It may be fairly definite, or so indefinite as to leave very considerable latitude to the participants (as in a casual conversation). But at each stage, some possible conversational moves would be excluded as conversationally unsuitable.

Cooperative Principle: Make your conversational contribution such as is required, at the statge of its occurence, by the accepted purpose or direction of the talk exchange in which you are engaged.

• Quantity

  1. Make your contribution as informative as is required, for the current purposes of the exchange.
  2. Do not make your contribution more informative than is required.

• Quality
  Try to make your contribution one that’s true, i.e.

  1. Do not say what you believe to be false.
  2. Do not say that for which you lack adequate evidence.

• Relation
  Be relevant.

• Manner
  Be perspicuous.

  1. Avoid obscurity (隐晦) of expression.
  2. Avoid ambiguity.
  3. Be brief, i.e. avoid unnecessary prolixity (冗余).
  4. Be orderly.

Talk exchanges exhibit certain features that jointly distinguish coorperative transactions:

• The participants have some common immediate aim, although their ultimate aims may be independent and even in conflict. In characteristic talk exchanges, there is a common aim even if it is a second-order one, i.e. each party should, for the time being, identify himself with the transitory conversational interests of the other.
• The contributions of the participants should be dovetailed, mutually dependent.
• There is some sort of understanding that, other things being equal, the transaction should continue in appropriate style unless both parties are agreeable that it should terminate. You do not just shove off or start doing something else.

A participant in a talk exchange may fail to fulfill a maxim in various ways:

• He may quietly and unostentatiously violate a maxim, and hence in some cases liable to mislead.
• He may opt out from the operation both of the maxim and of the CP. He may say, indicate, or allow it to become plain that he is unwilling to coorperate in the way the maxim requires. For example, he may say “I cannot say more”, “My leaps are sealed” etc.
• He may be faced by a clash. For example, he may be unable to fulfill the first maxim of Quantity without violating the second maxim of Quality.
• He may flout a maxim (i.e. blatantly fail to fulfill it).

Characterizing the notion of conversational implicature:
A man who, by (in, when) saying (or making as if to say) that has implicated that , may be said to have conversationally implicated that , provided that:

1. he is to be presumed to be observing the conversational maxims, or at least the coorperative principle;
2. the supposition that he is aware that, or thinks that, is required in order to make his saying or making as if to say (or doing so in those terms) consistent with the aforementioned presumption; and
3. the speaker thinks that it is within the competence of the hearer to work out, or grasp intuitively, that the aforementioned supposition is required.

The presence of a conversational implicature must be capable of being worked out. This is because, even if it can in fact be intuitively grasped, the implicature will not count as a conversational implicature unless the intuition is replaceable by an argument. Instead, it will count as a conventional implicature.

To work out that a particular conversational implicature is present, the hearer will reply on the following data:

• the conventional meaning of the words used, together with the identity of any references that may be involved;
• the cooperative principle and its maxims;
• the context of the utterance;
• other items of background knowledge; and
• the fact (or supposed fact) that all relevant items falling under the previous headings are available to both participants, and both participants know or assume that this to be the case.

A general working out of a conversational implicature:
He has said that . There is no reason to suppose that he is not observing the maxims, or at least the cooperative principle. He could not be doing this unless he though that . He knows (and knows that I know that he knows) that I can see that the supposition that he thinks that is required. He has done nothing to stop me thinking that . He intends me to think, or is at least willing to allow me to think, that . And so he has implicated that .

Linguistic phenomenons flouting the first maxim of Quality:

• Irony (反讽)
• Metaphor (隐喻)
• Meiosis (缓叙)
• Hyperbole (夸张)

Converational implicature must possess the following features:

1. At least the cooperative principle is observed. A generalized converational implicature can be canceled in a particular case, either
   • explicitly canceled (by adding a clause stating/implying that the speaker has opted out), or
   • contextually canceled (if the form of utterance is used in a context that makes it clear that the speaker is opting out).
2. It is impossible to find another way of saying the same thing, which simply lacks the implicature in question, except where some special feature (denoted as “Nondetachability”) of the subsituted version is relevant to the determination of an implicature. In this case, one may expect a generalized conversational implicature that is carried by a familiar, nonspecial locution to have a high degree of nondetachability.
3. Initially, conversational implicata are not part of the meaning of the expressions to the employment of which they attach.
4. The implicature is not carried by what is said, but only by the saying of what is said, or by “putting it that way”.
5. The conversational implicatum is the disjunction of specific explanations of the supposition that the cooperative principle is being observed. In addition, if the list of these various possible specific explanations was open, the conversational implicatum would have just the indeterminacy that many actual implicata in fact seem to possess.

Conventional Implicature (惯例含意)

This category of implicature does not rely on the conversational context, but is instead carried by the words themselves.

Differences between Implicature and Presupposition

• Implicature is cancelable. If the speaker explicitly says that some implicature is not fulfilled, then the hearer will not try to infer it.
  Example:
  : Did you drink coffee?
  : I drank some coffee, but not much.
  B cancaled the implicature “drank a lot of coffee”.

• Presupposition is not cancelable. It would be fulfilled even if it is expressed in a negative sentence.
  Example:
  Expression 1: My brother is a doctor. (Presupposition: The speaker has a brother.)
  Expression 2: My brother is not a doctor. (Presupposition: The speaker has a brother.)
  The presupposition in Expression 1 still holds in Expression 2, which negates Expression 1.