Quine

 Quine is working at the interface between language and reality. The epistemological question in the case of inference was – a) what justifies the transition from one thought to another? b) What explains the logical validity of inferences? To this, Frege’s answer was sameness of conceptual content, which later became sameness of sense and sameness of reference. If we are talking about semantic understanding, the epistemological question is: a) how do we discriminate between correct and incorrect usage of a word? b) How do we know how to apply the word correctly? To these questions, Frege’s answer was through grasping sense because it is the sense that determines reference. The ability to draw correct inferences and semantic understanding are products of our conceptual capabilities. To possess a concept is to have a norm or a standard of judgment about an object and to understand correct and incorrect use of concepts. The objective side of the content of concepts concerns the ontological question. What is the sameness of content that explains the validity of inferences? What are the senses that determine the appropriate object for us? To what objective standards do our judgments adhere? The question is about how my thinking is related to an external reality in such a way that it reflects upon my conceptual practices. How is this relation to an external reality established in such a way that it has an epistemological and normative significance? How does such a connection allow us to reliably conclude about the existence of objects in external reality?

The key concept we are about to discuss is the concept of reference. For Frege, number-statements were about numbers as objects, and natural language misled us into thinking that they were predicate terms. Instead, number-words are like proper names or singular terms that refer to a particular object.  Russell takes the method of analysis forward and believes that Frege underestimated the extent to which natural language misleads us. It is because of this that Frege took definite descriptions to be like proper names. He posits senses to account for reference failure, not realizing that in many of these cases, the expressions used were not referring expressions at all. Once we realize this positing senses becomes redundant. What Frege took to be singular terms turned out to be quantifier phrases, and the semantic value of the phrase lies in second-level concepts.

Russell distinguishes between knowledge by acquaintance and knowledge by description. The former is immediate knowledge of what is present before us, and the latter is mediate knowledge (e.g., Socrates, a philosopher who lived in Athens). Only those expressions can be regarded as referring expressions that provide us with knowledge by acquaintance. So only demonstratives like ‘this’ and ‘that’ are proper names. Macro-level objects that we are familiar within everyday world and even mathematical objects are constructed from sensory data and are regarded as logical fictions.

Quine would object to this because Russell assumed that we have a theory-neutral way to refer to external reality. For Quine, all referring expressions are theory-laden because we can refer to objects only within a theoretical framework. The meaning of words is determined by what role they play within theory.  The question – what exists is transformed by Quine into the question – what entities does my best theory about the world quantify over? The ontological commitments of the theory are not embodied in proper names, which can be analyzed away into hidden quantifier phrases, but in the existential quantifier. This quantifier is read as – there is atleast one such object. It says we are committed to the existence of this object, hence it marks the ontological commitments of a theory. Even ‘observation sentences’ are not theory-neutral. Observation sentences are sentences used to express assent or dissent based on a stimulus. Quine says they are holophrastic, or they have meaning as a whole sentence. Quine is a semantic holist and believes that sentence-meaning is prior to word-meaning and the former determines the latter. The meaning of a word is the role it plays within a theory. Observation Sentences Quine says are Janus-faced. When a child responds to a stimulus with an expression that ‘ah’, this word is not inferentially connected to any other word of the sentence. Hence, it seems that observation of stimulus allows the intake of a theory-neutral world of objects. But as the child learns a language, he also learns a theory about the world. He learns to parse his stimulus as object-like that have certain identity conditions, that persist through time and space and can be recognised after their position is changed and after a certain time has lapsed. Now his words have a certain inferential connection to other words in the language, and through this connection, they become meaningful and not just unstructured responses. Now observation sentences can be seen to have epistemological value, indicating the existence of objects, but the role they play is relative to a theory. So, the question – what exists can be answered from within the standpoint of a theory. But which theory about the world is best? We cannot choose a theory from an external standpoint. What counts as true or false depends on a theory, but the theory itself cannot be judged from a theory-neutral standpoint or from God’s eye view. Our best physics is our best theory about the world, and the objects that our best theory posits to make successful predictions about the world are objects we are committed to count as real or rather, should be considered to be real. But competing theories of physics can support incompatible ontologies, in which case we have a pragmatic choice of going along with the simplest theory that we have.

Quine, like Frege, does not believe that mental images can fix reference and contrary to Russell, he does not believe that knowledge by acquaintance can fix reference either, because we do not have the kind of immediate access to the world as Russell believed we had. The same perceptual data comes out as compatible with different interpretations of its ontology. Also, contrary to Frege, he does not believe senses fix reference. The Fregean ‘senses’ are abstract objects that are objective and publicly shareable, that mediate between us and the world. If there are such ‘senses’, Quine’s challenge is that we can make sense of the concept of synonymy or sameness of meaning because anything that exists must have clear-cut identity conditions. However, sameness of meaning cannot be explained through either analytic or synthetic statements. Analytic statements are regarded as true by virtue of their meaning, like the sentence ‘All bachelors are unmarried men’, and synthetic statements are informative about how the world it like ‘Delhi is the capital of India’ – their truth or falsity cannot be known through the meaning of words alone but through knowing how things are in external reality. Analytic statements do not explain the concept of sameness of meaning because they presuppose that concept. Nor can we understand sameness of meaning through the principle of substitution salve Veritate. According to this principle, substitution of one term for another with the same reference or the same sense does not change the truth value or the sense of the sentence as a whole. But there are terms like ‘creature with a heart’ and ‘creature with a kidney’; the substitution of these terms would keep the truth value of the sentence intact, but they do not mean the same thing.

The problem becomes more acute with the thought experiment Quine conceived to make his point. The argument shows that there is no objective standard that determines the difference between correct and incorrect usage.  Quine would adopt the standard sceptical strategy that anything that we can take to fix the reference for us and so determine what counts as correct use of a word from an incorrect use, will fail to produce a unique criterion because it will not be able to discriminate between one way of using the word and its opposite.

Now, imagine there is a translator who seeks to translate a foreign language with which he has no prior acquaintance whatsoever. The only data available to him would be observable – his target’s linguistic behaviour. Mental images are unavailable to the translator, and since he has no prior knowledge of this language, he cannot know what the foreigner’s words mean. The translator observes how the foreigner responds to the word ‘gavagai’, and he notes that the foreigner assents to using this word whenever there is a rabbit present and dissents whenever it is absent. So, the translator assumes that ‘gavagai’ means rabbit. But Quine points out that the foreigner’s linguistic behaviour is compatible with very different ontologies. The word ‘gavagai’ can mean undetached rabbit-parts or a space-time complement of a rabbit. The translator for clarification, asks the foreigner whether this gavagai is the same as that gavagai. The word for indicating sameness or identity in the foreigner’s language is ‘emas’, but the translator cannot know for certain whether ‘emas’ means the same as undetached rabbit-part or the same space-time complement of a rabbit. The translator cannot know whether he uses words indicating identity in the same way he does. The translator can come up with two radically incommensurable translation manuals supported by the same observable evidence, neither of which would fix the correct ontology ascribable to the foreigner for us. The translation manuals would be incommensurable because if they are used simultaneously, all communication would break down. But keep in mind this is a thought experiment, and Quine does not believe we do have such incommensurable conceptual schemes at all – only that our empirical evidence can support such radically incommensurable theories.

What this thought experiment shows is that two radically different ontologies can be justified by the same set of sensory evidence and hence the correct ontology is underdetermined by our total evidence. The experiment has given rise to a misunderstanding about what underdetermination means, and it is assumed that more empirical information would allow us to tell what the foreigner actually means. To resolve this misunderstanding that indeterminacy is different from underdetermination by evidence, because the former is about underdetermination relative to all physical evidence that we can possess. So, a complete science too would not be able to uniquely determine an ontology for us, and it would be compatible with two radically incommensurable ontologies.

So, we need to distinguish inscrutability of reference from radical indeterminacy. The former arises at the level of words, and the latter is holophrastic or arises at the level of sentences or theories as a whole. The former does not prove that there is no fact of the matter that determines correct usage of a word, but only that we do not have access to such facts. Quine is after the stronger conclusion that our total set of empirical evidence cannot fix a uniquely correct ontology. With further empirical information, we can fix word-meanings, though they are underdetermined by available sensory evidence, and word-meanings are fixed at the level of sentence meaning or the theory as a whole. But if the theory itself is under-determined by all available evidence and this theory covers all facts whatsoever, then the under-determination becomes serious.

Quine seeks to prove that no fact of the matter determines a correct ontology for us because the question of what exists is meaningful and can be answered relative to our theory about the world. This theory makes contact with the world as a whole or a corporate body, and the validity of this theory cannot be answered by any external or theory-neutral standpoint. Hence, science, which is an extension of our theory about the world, has its validity is proved from within the ambit of the scientific method itself. And the question of what exists and does not exist or what is true or false, can be raised and answered from within a scientific perspective, or they cannot be answered at all.