20th WCP: Problems of Mind as Action

I. Introduction

This is a paper on the nature of philosophical theory of mind. It is not on all aspects of philosophy of mind. The main problem is the way of talking about mind. My intention is to present the claims, problems and arguments concerning the mind in a way that will make them comprehensible for those who are coming to the philosophy of mind with some general philosophical background. Over the past two decades philosophy of mind has been unusually active and exciting area. There are significant advances in our understanding of the mind. A large body of literature has built up during this period [9,10,11]. Partly this boom has been due to the stimulus provided by the explosive growth of cognitive science with aspiration to improve the scientific understanding of mind. Cognitive science is an interdisciplinary approach to cognition that draws primarily on ideas from cognitive psychology, artificial intelligence, linguistics and logic. Some philosophers may be cognitive scientists, others concern themselves with the philosophy of cognitive psychology and cognitive science. Since inauguration of cognitive science these disciplines have attracted much attention from certain philosophers of mind. This has changed the character of philosophy of mind, and there are areas where philosophical work on the nature of mind is continuous with scientific work. In this paper I shall try to stay with the problems that are standardly and traditionally regarded within philosophy of mind rather than those that emerge from the recent developments in cognitive science.

II. Problems of Philosophy of Mind

Philosophy of mind is defined by a group of problems. The problems that constitute this field concern the ways of thinking and mental properties. What are some of these problems? And how do they differ from the scientific problems about mental properties, those that cognitive scientists, and neuroscientists investigate in their research? The first of all is the clarifying the concept of creature with a mind. Before, we can answer all other questions, we need a clear idea about our conception of mind itself. This general question is difficult to answer with explicit definition. Therefore here is the clue question of what constitutes mind. The second group of questions is concerning the relationship between emotions in all their forms and cognitive components of human mind. What is a knowledge and how does knowledge get to have the content it has? A third group of problems concerns the relation between mental and physical properties. Collectively they are called "the mind-body problem". This problem is central question of philosophy of mind since Descartes formulated it three centuries ago [1, p.148-208].

This problem of clarifying and making understandable the relation between mental and physical properties. What needs to be clarified and explained here is this: because mental seems utterly different from the physical and yet the two seem intimately related to each other. When we think of consciousness it is hard to imagine anything that could be more different from mere configurations and motions of material particles, atoms and molecules, cells and tissues. How can such conscious events emerge in biological systems? How can biological systems come to have such mental states as thoughts, hopes, experience of guilt and embarrassment? It strikes many of us that there is a fundamental, qualitative difference between biological properties and mental properties and that this makes their apparently intimate relationships puzzling and mysterious. What are these relationships?

Various characteristics have been proposed by philosophers to serve a criterion that would separate mental properties or phenomena from those that are not mental. Each has a certain plausibility and covers a range of mental phenomena, but none seems to be adequate for all the diverse kinds of events and states, functions and capacities that we normally classify as mental. A review of some known arguments will give us an understanding of the principal ideas that have traditionally been associated with the concept of mind and highlight some important characteristics of mental phenomena. But no single of them seems capable of serving as a universal necessary and sufficient condition of mentality. Mind possess a number of important properties that turn out to be interesting for the philosophy of mind. From our point of view, the human behaviour and activity discerns the most properties of mind. Therefore I thought to discuss some positions from this perspective.

III. Mind as Behaviour

Introductory texts in the philosophy of mind often begin with a discussion of behaviourism, presented as one of the few theories of mind. This theory has been refuted, but matters are not that simple and behaviourism is still alive. Term behaviourism covers a multitude of positions. Yet there is a common underlying thread. The behaviourists take minds not be inner psychic mechanisms merely contingently connected with their outer behavioural effects, but to be constituted by those outer effects. Behaviourism arose as a doctrine on the nature and methodology of psychology in reaction to the subjective and unscientific character of introspectionist psychology. William James defined the scope of psychology in these words: "Psychology is the science of mental life, both of its phenomena and of their conditions. The phenomena are such things as we call feelings, desires, cognitions, reasonings, decisions, and the like"[2, p.15 ]. For James, psychology was the scientific study of mental phenomena, and he took the study of consciousness as an important core of psychology. Compare this with the declaration of J.B.Watson, who is generally considered the founder of behaviourist movement: "Psychology... is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behaviour" [3, p.25 ]. This view of psychology as the study of publicly observable human and animal behaviour, not of inner mental life, dominated scientific psychology and associated fields.

The rise of behaviourism and the influential position it attained was no miraculous. Even James saw the importance of behaviour to mentality. He wrote: "The pursuance of future ends and the choice of means for their attainment are thus the mark and criterion of presence of mentality in a phenomenon. We all use this test to discriminate between an intelligent and a mechanical performance" [2, p.21]. It will be agreed on all sides that behaviour has a lot to do with mentality. But what is relationship between them? Does behaviour merely serve as an indication, or a sign, that a mind is present?

Philosophical behaviourism takes behaviour as constitutive of mentality. According to this position, having a mind is a matter of exhibiting certain appropriate patterns of observable behaviour. But philosophy knows other approach to mind. Traditional conception of mind derives from Descartes and his followers. Descartes wants to say that his mind is no less substance than his body or that his mind is no less basic a thing than his body. He means that his mind does not depend for its existence on his body. The dualist position means that he, his mind could exist even if his body did not. If the mental is essentially private and subjective, it is mysterious how we could know other minds, how we could ever learn the meaning of the words. Behaviourism is a reaction to Cartesian conception. It attempts to construe the meanings of our mental expressions. It means to understand the meanings of our mental expressions as publicly acceptable and intersubjectively verifiable conditions and facts about people. According to the behaviouristic approach the meanings of mental expressions are to explained by reference to facts about publicly observable behaviour. But what is behaviour?

Often we describe behaviour as action. Behaviourism that is discerning the mind in action is concessive to the idea of the mental, since the mental is treated as genuinely present in patterns of action. But there is behaviourism which makes no such concession. Its adherents insist that there are brains and there is behaviour, but that mental states are just surplus to requirements. Concessive behaviourism counts to seeing the mind as presented in complexes of actions and tendencies to act. Term behaviour means whatever people or organic systems do that is observable. Such doing must be caused by some occurrence internal to the behaving system.

We can distinguish several types of action: (1) Physiological reactions and responses (perspiration, salivation, increasing of blood pressure); (2) Bodily motions (rising of arms, moving toward something); (3) Actions involving bodily motions (greeting a friend, checking a book, shopping ,writing, telephoning); (4) Actions not involving overt bodily motions (reasoning, guessing, calculation, judging, deciding). Public observability is central concern to behaviourists. Therefore they will exclude items under (3) and (4) as behaviour, counting only those under (1) and (2). Mental acts are inner events and behaviourists will not consider them as behaviour in their intended sense. In behaviourist literature there is an implicit assumption that only those physiological responses and bodily motions that in a broad sense overt and external are to count as behaviour. This would preclude events and processes occurring in the internal organs as behaviour. Thus internal physiological states, including states of the brain, would not, on this view, count as behaviour, although they are of course among the physical states and conditions. The main point is that behaviour is taken to be bodily events and conditions that are publicly observable.

To solve this problem we should distinguish between physical and agential behaviour. Physical behaviour is a physical change to an agent 's body. The relationship between physical behaviour and agential behaviour is controversial. On some views, all actions are identical to physical changes in the agent's body. On others, an agent 's action must involve some physical change, but is not identical to it. Anything a person can do, even calculating in his head, could be regarded as agential behaviour. Likewise, any physical change in a person's body could be regarded as physical behaviour. To claim that the mind is nothing over and above such kinds of behaviour is not necessarily to be a behaviourist. The theory that the mind is a series of volitional acts and the theory that the mind is a certain configuration of neural events are not the forms of behaviourism. Either the behaviourist needs a less inclusive notion of behaviour or if he does allow some inner processes to count as behaviour, he must minimise their importance. Waving to someone are more behaviouristically acceptable than calculating in the head. If a philosophical theory of the mind emphasises waving over silent cogitations and brain events, then it is behaviourist. This position defines the eliminative behaviourism.

IV. Eliminative Behaviourism

Eliminative behaviourism is predecessor of the contemporary doctrine of eliminative materialism. This position is radical version of physicalism. Eliminativists repudiate all concepts of our mental ontology: beliefs, conscious states, sensations , and so on. They admit bodily sensations and perceptual experiences into their ontology by identifying them with physical brain states. Although the view is radical, the arguments for it are fairly straightforward.

Some arguments of eliminativism are these. First, our tacit theory of the behaviour of others suffers various deficiencies, for instance, widespread explanatory failings. We should think of beliefs and desires as the posits of a theory of the causes of behaviour. When we say that Joseph has begun to study law because he desired to be politician, we are hypothesising that Joseph 's behaviour has certain inner causes. Generally, when we predict and explain behaviour in terms in beliefs, desires, hopes, we are explaining behaviour on hypothesis that subjects have inside them inner causes of behaviour. We should understand talk about beliefs and desires as a talk about posited inner causes of behaviour. Eliminativists have fond our everyday talk of beliefs and desires a folk theory (folk psychology) to emphasise that it is a set of pre-scientific opinions held by the folk and point out that we have many folk theories: folk physics which includes common opinion about bodies move; folk nutrition, which includes common opinion about diet, and so on.

Second, there are much better theories of behaviour which do not quantify over mental states. Therefore, in accordance with good scientific practice, folk psychology should be replace by one of these superior theories. The history of science is full of examples of theories whose posits turned out not to exist: witches, demons, caloric fluid, phlogiston, the ether, vital spirits. These are just some examples of entities, states and properties posited to explain various phenomena, which turned out not to exist. Eliminativists argue that folk psychology has a number of disturbing similarities to the discredited theories. Folk psychology has all the sighs of what Imre Lakatos called a degenerating research programme. It is an old theory that has hardly changed since it was first developed. There is a new theory that promises to do all that it does. As Aristotelian physics was replaced by Newtonian physics, which in turn was replaced by relativity theory and quantum theory, and as Ptolemaic astronomy was replaced by Copernican and Keplerian astronomy, so the eliminativist urges that all the evidence points to folk psychology being replaced in the future by a neuroscience that provides us with new explaining and predicting behaviour.

Eliminative behaviourism is a dominant theme in the wrightings of Watson [4 ] and Skinner [5 ]. According to the introspective school, the subject matter of psychology is consciousness, and the proper methodology for its study is introspection. Against this, Watson argued that a scientific psychology should just concern itself with what is objective and observable, namely, behaviour. Watson and Skinner both thought that the behaviour of an organism could be explained by its history of stimulation together with relatively simple processes of behavioural modification. They both had a strong tendency towards eliminativism.

An another eliminative behaviourist is Quine, but for quite different reasons. His behaviourism appears to be motivated largely by his verificationism. He gives two reasons for eliminativism. The first is that belief and desire talk resists regimentation in first order logic, which Quine takes to be the test for complete intelligibility. The second is his argument for the thesis of the indeterminacy of translation, which purposes to show that there is simply no fact of the matter as to what someone's language means[6 ]. Quine assumes a sufficiently intimate connection between language and belief for in to follow that there is also no fact of the matter as to what someone believes.

V. Analytic Behaviourism

Most behaviouristically inclined philosophers are not eliminativists. The most powerful and straightforward kind of noneliminative behaviourism is analytic behaviourism that derives from view that all statements containing mental vocabulary can be analysed into statements containing just the vocabulary of physical behaviour. Hempel can be interpreted as an analytic behaviourist. He is stating a view common to many logical positivists: "All psychological statements which are meaningful, that is to say, which are in principle verifiable, are translatable into statements which do not involve psychological concepts, but only the concepts of physics" [7, p.18]. Hempel derived this thesis from two premises. First, he held the verificationist theory of meaning, namely that the meaning of a statement is established by its conditions of verification. Second, he held that a person 's physical behaviour was a large part of the evidence for ascribing to him particular mental states. Putting the two together, he concluded that statements about mental states were equivalent to statements about physical behaviour.

Hempel was not a thoroughgoing behaviourist in the sense of ignoring inner processes altogether. According to Hempel, the verification conditions of "Paul has a toothache" include certain changes in Paul's blood pressure, his digestive processes and his central nervous system. But as bodily movements play a large role in the verification of psychological sentences, and hence play a large role in determining their meanings.

Interesting views on the mind as behaviour develops Gilbert Ryle [8]. His position is also often called analytical or logical behaviourism, but it is quite different from the positivist sort of behaviourism exemplified by Hempel. Some behaviourists have accepted the idea that there simply are no phenomena of mind, that the mind is a kind of fiction superimposed on the complex movements of human bodies. Such an extreme eliminativist behaviourism was certainly never part of Ryle 's project. However, there is a kind of behaviourism which treats the mind not as fiction but as definable in terms of behaviour. The real question is how far Ryle can be understood as advocating this sort of view.

Ryle regarded the very question of whether the world is ultimately physical as conceptually confused. He spoke of agential behavioural dispositions, and showed little inclination to analyse this away in terms of physical behavioural dispositions. Ryle was chiefly concerned to deflate the idea that there must be complex inner mental processes behind a person 's public actions and to show how this dissolved the problem of other minds. Ryle speaks about "category mistakes", which consists in taking one kind of thing for another as when the confused tourist says that he has seen all the college buildings in Oxford, but has yet to find the University. What the tourist has failed to appreciate is that the University is a different kind of thing from colleges and buildings. Applied to the mind, the idea seems to be this: it is easy to be misled into thinking it is a special kind of thing, different from, but belonging to, the same general category as the matter that makes up the physical world. According Ryle, "the hallowed contrast between mind and matter will be dissipated, but dissipated not by either of the equally hallowed absorptions of mind by matter or of matter by mind" [9, p.23 ]. He suggests that when one tries to find the difference between intelligence and lack of it, one should not look for some special mind stuff, the operation of which makes someone intelligent. One should be asking by what criterion intelligent behaviour is actually distinguished from non-intelligent behaviour. In this and in numeral other examples Ryle suggests that the mind consists in patterns of behaviour and that to think otherwise about it is precisely to categorise it wrongly. In Ryle's examples, behaviour is always treated as fully intentional, there is no attempt to characterise it in non-mental, physical terms. In spite of the difficulties of interpretation, Ryle's conception of mind contains a specific, important insights into mental processes. Some of the things Ryle says might even encourage one to think his position is an early form of functionalism.

VI. The Functionalist Idea of Mind

Thinking of things as physically constituted is sometimes a misleading way of trying to understand them. The identity theory treats mental phenomena as something like car. For example, understanding a believe involves understanding how each of them is embodied in some physical realm such as the central nervous system. But perhaps a better way to think of beliefs is understood only what each of them does. The idea, that we understand specific mental phenomena by describing what they do, is at the heart of the view known as functionalism. One of these versions is currently the most popular way to achieve coalescence between the mental and the physical. It is not obvious what it means to say that we understand a belief when we know what it does, what its work or function is. If we describe how the believe affects my behaviour and other mental states as output and the sources of its formation as input, then we can say that functional role of the belief is some specific set of complex inputs and outputs. The complexity should not prevent one seeing the core idea of functionalism that a mental phenomenon will be defined by its inputs and outputs, its functional role. In spite of talk about inputs and outputs, a functional account is not itself a behaviourist account. Behaviourists considered earlier aim to define such mental items as beliefs as patterns of behaviour, whether actual or potential. In contrast, a functionalism allows that beliefs and relevant behaviour exist independently of any behaviour. Indeed, mental states cause various patterns of behaviour and they cannot be defined in terms of them. Among the inputs and outputs that constitute the activity of belief there are jump to be other mental states.

The functionalist is someone driven by a particular conception of the mental, that allows the token identity thesis and multiple realizability as ways of guaranteeing the physical character of the mind. It is perfectly conceivable that one could embrace the core functionalist idea without going the token identity forward. There are two ways in which this could happen. On the one hand, one might be a functional dualist: someone who thinks that mental items are to be understood in terms of their characteristic work, without regarding the mind as in any way material. On the other hand, one could be a functional reductionist: someone who thinks that the mental is type identical to the physical and to that reducible.

It is one thing to think that the core functionalist idea is attractive, it is another to describe it in the sort of detail necessary to establish its plausibility. For the functionalist position is characteristically that one can list all states and events leading to concrete mental function. Believing of all inputs and outputs is enormously complex to list them. What grounds the widespread conviction among philosophers of mind that functionalism of some sort has any chance of success? The large degree of functionalism interest in details has a very solid foundation. For certain important results in the theory of commutation have shown that complexity is no real obstacle to the project of functionalism. Turing shown that any complex pattern of interrelation between inputs and outputs could be imitate by very simple and orderly functional relations which have been called "Turing machines".

Turing machine has had a major influence on the thinking about the mind. To see why this is so, one must first accept that mental phenomena are dependent on the relations between inputs and outputs which are describable by various mathematical relationships. Turing machine is essentially a very simple sort of computer program which can transform certain inputs into some outputs. Turing machines take any two numbers as input and produce their sum as output. There are no patterned relationships between inputs and outputs so complex as to escape some Turing machine. So the core idea of functionalism can be accepted.

The using of the Turing result consists in treating such things as beliefs, desires, pains and other mental items as themselves states of a Turing machine appropriate to the mind being. Various features of the mental and Turing machine states have made the machine functionalism the preferable option. At the other extreme is the view that treats the conception of mind which supported by the Turing results but which does not attempt to make any direct connections between Turing machines and mental items. These view insists on the functional characterisation of the mental. There are also a range of views that regard the common-sense conception as tied to some computational level of description. Only outlines the possibilities brings out something important about the connection between functionalism and computational accounts. It is fact that there is a certain connection between them. From this view comes the arguments that the mind is a computer program. On the one hand, there are those who regard this interpretation as no more than a metaphor, and there those who think it literally true. It is not surprising that there should be this difference. If we regard mental items as computational states, then the mind will count for us literally as a computer. But if we only think of mental as grounded on the possibility of a computational account of our neural workings, then the most would allow that the mind is like a computer program. These views give important thought about the functionalist idea that the mental is multiply realisable.

Multiple realisability is a feature of functionalism that has occasioned much discussion. This feature means that functionally defined systems abstract from most physical properties can be realised in an indefinite variety of physical substances. One can describe a causal organisation without committing to specific features of the realisation of that organisation. The example of the Turing machine is paradigmatic: our mental items could be realised by any number of physically different mechanisms. Turing machines states can be realised in transistors, in electron tubes, in silicon. Turing machines are not actual concrete machines, but rather the specifications of highly idealised machines. Turing machine can be defined purely mathematically. It helps in thinking about one to imagine some physical device that "realises" the specification. Standard computer programs can be run on very different kinds of machines with often different parts playing the same functional role in the program. Similarly, political and economic institutions can be realised by different people and physical things.

By virtue of this multiple realisability, functionalism with regard to the mind has three important consequences: philosophical, practical, methodological. The philosophical consequence consists in its capturing of the intuitions that we are prepared to find most anything inside people's heads. A practical consequence of multiple realisability is that it permits the possibility in principle of replacement of dysfunctional parts of the brain. It is a truism these days that the chemistry of our brain is often not optimal: depression, violence, attention disorders seem to be due to various imbalances in hormones and neuroregulators. Now if someone's mental life depended upon a person's being made of specific chemicals nature has provided, it would appear that all we could do is perhaps change the balance in these chemicals. But, if a person's mind is multiply realisable, then it becomes a serious option to search for the chemicals that would play the same role in the healthy mind's organisation, but without the deleterious effects.

The important consequence of functionalism is a methodological one. It permits a level an autonomy it can enjoy without for a moment denying the reality of physical level. If functionalism is correct, then studying merely the physiology of those states in the absence of that organisation would be explanatory inadequate. If we return to computer analogy, studying the physics of transistors would be irrelevant to learn how a word processing program works. Many computer programmers have a profound understanding of the algorithms for computing certain functions without having a clue about the electrical properties of the machine on which those algorithms might be run.

VII. Mind as Action

The first of sources of contemporary seeing of the mind as behaviour and action derives from functionalism. According to this view, the meanings of mental terms are determined by their role in our common-sense theory of behaviour. This tacitly known theory is taken to consist of generalisations linking perceptual input, behavioural output, and mental states. Functionalism says that mental states are constituted by their causal relations to one another and to sensory inputs and behavioural outputs. Functionalism is one of the major theoretical developments of modern analytic philosophy, and provides the conceptual foundations of much work in cognitive sciences. According to analytic functionalism, one may reasonably conclude that a creature has a mind on the basis of its behaviour, just as one may reasonably conclude that a car has an engine on the basis of its motion. The second source is opposition to the functionalist idea that an organism needs a certain kind of inner causal organisation in order to be a genuine believer. The third source is Wittgenstein attack on the possibility of a "private language", which shows that meaning and belief must be manifestable in behaviour. Corresponding to these three source we can formulate the next theses.

Behaviour is the necessity of mind.. Anything that has no physical behavioural dispositions of a certain kind and complexity does not have a mental life. This vague formulation should be taken to express the behaviourist thought that something like a stone could not possibly have a mental life, because it is inert. There cannot be a race of thinking stones. To refute the view that a certain level of behavioural dispositions is necessary for a mental life, we need convincing cases of thinking stones, or disembodied minds. But these alleged possibilities are to some merely that.

Behaviour is a sufficient proper of mind. Anything that has physical behavioural dispositions of certain kind and complexity has a mental life. According to functionalism, whether of the analytic variety or not, minds must have some specific type of inner causal structure. Functionalism in general is therefore inconsistent with the behaviour as sufficient view. Dennett, for example, has been a long-time opponent of the idea that to have a mind is to have a specific type of inner causal structure. On the one hand, Dennett is unmoved by thought experiments which purpose to show that having a mind involves some restriction on inner causal order. On the other hand, he is impressed with the remarkable predictive power of everyday psychology. Adopting the "intentional stance" is indispensable in many cases, its utility not diminished by any discoveries of bizarre inner causal organisation. "Any object-whatever its innards-that is reliably and voluminously predictable from the intentional stance is in the fullest sense of the word a believer" [9, p.137]. To refute the view that a certain level of behavioural dispositions is sufficient for a mental life, we need convincing cases of rich behaviour with no accompanying mental states.

The thesis that the mental is supervenient on the physical has played a key role in the formulation of some influential positions on the mind. Donald Davidson was first to introduce supervenience into discussion about nature of mind. He wrote that "mental characteristics are in some sense dependent, or supervenient, on physical characteristics. Such supervenience might be taken to mean that there cannot be two events alike in all physical respects but differing in some mental respect, or that an object..." [9, p.576]. Psychological facts supervene on physical behavioural dispositions. If x and y differ with respect to types of mental states, then they differ with respect to types of behavioural dispositions. Supervenient behaviourism may be broadened to include the supervenience of linguistic meaning on behavioural dispositions and accommodate the view that content is not entirely in the head by taking the supervenience base to comprise physical behavioural dispositions together with facts about the subject environment. Supervient behaviourism is quite compatible with eliminativism. However, some philosophers who repudiate eliminativism are attracted by supervenient behaviourism. More precisely, these philosophers hold a doctrine about the mind, which, together with assumptions they would probably accept, entails supervenient behaviourism. In the writings of Davidson there is a thought that holds that someone has under ideal conditions complete and infallible access to his own mental life. The third-person version says that someone has under ideal conditions complete and infallible access to the mental life of another. According to Davidson, "there is no good reason to suppose that having a prepositional attitude requires an entity which the mind entertains or grasp. Having an attitude is just being in a certain state; it is a modification of a person. There need not be any "object" in or before the mind for the person to be thinking, doubting, intending or calculating... Such objects serve much the same function as numbers serve in keeping track of temperature or weight" [9, p.232 ].

Understanding the mental states of others and understanding nature are cases where questions come to an end at different stages. The measurement of physical quantities has intersubjective character. Success in interpretation is always a matter of degree: resources of thought or expression available to an interpreter can never perfectly match the resources of interpreted. It is always possible to improve one's understanding of another mental life by learning more about the things we are know about. This is the process of interpretation where is not impersonal objective standards which to measure our own best judgements of the rational and the true. Here lies the source of the ultimate differences between the concepts we use to describe physical events and mental property. It is impossible to come to agree on ultimate common standards of rationality. It is our own standards in each case to which we must turn in interpreting others. This should not be thought of as a failure of objectivity, but rather as the point at which questions comes to an end. We cannot in the same way go behind our own ultimate norms of rationality in interpreting others. We would have no full thoughts if we were not in communication with others, and therefore we have not thoughts about nature. Communication requires that we succeed in finding something like our own patterns of thought in others.

What someone means by what he says depends only on what is in his mind. The situations in which words are learned merely constitute evidence of what those words mean, rather than conferring meaning on them. What someone means depends on what others in his linguistic community mean by the same words. If everyone is speaking in his own way how each speaker is to be understood. The understanding, agreement between speakers is nothing more than shared expectations: the hearer expects the speaker to go on as he did before, the speaker expects the hearer to go on as before. However, there can be differences between our expectations and the real content of speaker 's words. It has been influenced by our learning that involves such elements: (1) the "teacher", which may be teacher, community of speakers, speech of all objects and events surrounding our existence; (2) the "learner", who may be entering a first language, or consciously trying to decipher another; (3) a shared world. Without the external world shared through ostentation, there is no way a learner could discover how speech connects with the world. Without a "teacher" nothing would give content to the idea that there is a difference between getting things right and getting them wrong. Only those who communicate can have the concept of an intersubjective, objective world.

From this thought follows others. If only those who communicate have the concept of an objective world, then only those who communicate is to recognise the existence of other people in a common world. Language, that is communication with others, is essential to human thought. It is necessary to have the words to express a thought, it gives the sense of objectivity that has its ground in the intersubjectivity.

The characteristic feature of mental states is that people usually know that it is in them without appeal to evidence or inference. We can know what we think, feel, want and we know this with a special kind of certainty that contrasts with our knowledge of the physical world. For whatever one 's conception of mind and matter, there does seem to be an asymmetry between our knowledge of our own mind and our knowledge of external world. One way to put it is to say that a subject has first person authority with respect to the contents of his mind, whereas others can only get at these contents indirectly. You count as an authority about your own mind because you can know about it directly and this is very different from the type of knowledge others can have. The notion of first-person authority shows why the external determinants of meaning do not threaten our knowledge of the character of our own thoughts. The interpretivism is an idealisation of human being in ideal epistemic circumstances. The ideal interpreter is capable, according to interpretivism, of discovering exactly what a subjective believes and desires. But the power of the interpreter is a matter for discussion.

Intepretivism does not entail supervenient behaviourism. For it may be that the interpreter must take into account certain non-behavioural facts determining what someone believes. Davidson 's "observable behaviour" is intended to be understood as "behaviour observable as physical behaviour". For suppose that the relevant deliverances of observation include linguistic behaviour such as saying that snow is white.