Philosophy of mind is a branch of analytic philosophy that seeks to study the nature of mind, as well as its relationship to the physical world. The mind-body problem understood in the broad sense, the problem of the relation of mental states to the body, is commonly considered to be the central question in the philosophy of mind, although other questions about the nature of mental states do not concern the body, or refer directly to the environment (physical or social) of individuals. Philosophy of mind can also question the very reality of mental phenomena, thereby accepting the possibility that mind does not exist as we conceive it or as we experience it “from within”. Historically, mind-body dualism and materialism are the two main schools of thought that have provided an answer to the question of the nature of mind and its relationship to the physical world.
The philosophy of mind aims to understand the nature of mental phenomena, not directly on empirical grounds, but mainly through an analysis of mental concepts. In this sense, it differs from cognitive psychology, which is an empirical study of mental phenomena concerning the organisms in which they appear. It is also distinct from the philosophy of psychology, which is a study of the methods, concepts, and results of empirical psychology. Its major specificity, from which also stems its main difficulty, resides in the fact of having to explain how the same mental phenomena can be aimed at through the two perspectives, apparently incommensurable, that are the point of view “in the first person” (subjective ) which seems to let us experience them directly “from the inside”, and the “third person” (objective) point of view based on observing the “outside” behavior or the brain.
One way to understand the philosophy of mind project is to think of it as the search for a third way between the Cartesian and behaviorist paradigms. While the Cartesian attitude gives priority to introspection, that is to say to the first person perspective – the other perspective allowing only indirect access to mental phenomena – the behaviorist attitude, on the contrary , insists on the need to stick to the third person perspective, the one adopted by an outside observer. Faced with the many difficulties implied by these two antagonistic attitudes, the philosophy of mind today presents a range of theories which attempt to reconcile the subjective and objective approaches. However, these theories most often give priority to the second type of approach, espousing the point of view of the natural sciences within the framework of what is now agreed to be called naturalism. The physicalist ontology, for which only the physical world described by the natural sciences really exists, therefore appeared as the dominant ontology from the first developments of the philosophy of mind.
In philosophy of mind, the term “materialism” generally refers to physicalist conceptions of the reductionist and eliminativist type, and more particularly the so-called theory of mind-brain identity. Indeed, physicalism can be non-reductionist, and in this sense cannot be assimilated to materialism stricto sensu. The non-reductionist approach essentially corresponds to functionalism, although the latter can also be defended within a reductionist framework. Even outside Cartesian dualism, there are of course alternatives to physicalism, the main ones being emergentism (in its strong version) and panpsychism. Other currents do not comment on the nature of mental states, or are part of a purely axiological perspective. It should be noted that the notions of normativity and rationality share in philosophy of mind the same meaning which only partially covers the meanings given to them in traditional philosophy.
From the 17th century, with the development of the natural sciences, a number of philosophers like Descartes or Spinoza proposed different ways of understanding the place that the mind occupies in the physical world. But it was only with the emergence of cognitive science in the 1950s that a “naturalistic turn” in philosophy took place. The latter, since the end of the 19th century, with on the one hand Edmund Husserl as the founder of the phenomenological movement, and on the other hand Gottlob Frege as a precursor of analytic philosophy, was characterized rather by its anti-naturalist approach. Both Husserl and Frege, in fact, based their philosophy on a critique of logical psychologism, a kind of positivism which envisaged logical relations as natural thought processes. Against this conception of the mind which threatened to reduce philosophy to an empirical psychology modeled on the natural sciences, phenomenology and analytical philosophy insisted, each with very different approaches, on the need to distinguish from the empirical method of the sciences the properly conceptual approach of philosophy. In the post-Fregean context, Willard Quine was the first to react against this anti-naturalism, starting from a critique of the idea of a radical division between analytical statements and empirical statements. This criticism led him to question the specificity of the philosophy of mind in relation to the natural sciences and to envisage a “program of naturalization” of the mind.
Following Quine, many philosophical attempts to explain mental processes in terms of natural processes have been made. A common solution in the 1960s was to identify psychological states (perceptions, sensations, desires, beliefs, etc.) with neurophysiological states or processes in the brain. This strongly naturalistic and reductionist conception became known as the theory of mind-brain identity and was defended in particular by the philosophers John J. C. Smart and Ullin Place. She claims that neuroscience can help us understand how certain neurophysiological structures and processes in the brain relate to us as a mental life. Mind-brain identity theory was widely criticized in the 1960s and 1970s for its failure to account for the multiple realization of mental phenomena, which can be brought about by a variety of different mechanisms. This criticism of the identity theory constituted a point of agreement to seek other solutions to the mind-body problem within a naturalist but non-reductionist framework. These include computationalism (Jerry Fodor, Hilary Putnam), “anomalous” monism (Donald Davidson), and instrumentalism (Daniel Dennett). This research has also led to a veritable proliferation of objects of study as well as various specializations within the discipline. From the 1980s, the theme of consciousness became one of the most important there.
The mind-body problem
In the context of the philosophy of mind, the mind-body problem refers to a type of questioning about the nature of the relationship that the mind has with the body, in particular with the brain. This problem is due to a theoretical obstacle which essentially consists in the fact that there are good reasons for admitting certain theses which are nevertheless judged to be contradictory when they are considered together. These theses can be summed up in the following three propositions or principles :
- Mental states are not physical states: mind-body duality principle (1)
- Mental states cause physical states, and vice versa: principle of mind-body interaction (2)
- Every physical state has complete physical causes: principle of physical completeness (3)
The first two propositions are based on the experience we have of ourselves – we seem to have a body on which our mind can act and on which it also depends – while the third proposition is based on the results of modern natural sciences. The success of these sciences indeed seems to indicate that for any physical state, it is never necessary to seek a cause for its production outside the field of study of physics. The crux of the problem is that these three propositions are compatible only two by two, each of these pairs of compatible statements implying the falsity of the third:
- (1) and (2) imply not (3): if mental states are not physical states but cause physical states, then the principle of causal completeness is false (this is the position of interactionist or Cartesian dualism)
- (1) and (3) imply not (2): if mental states are not physical states but any physical state has sufficient physical causes, then a mental state cannot be the cause of a physical state and the mind-body interaction principle is wrong (this is the position of non-interactionist dualism)
- (2) and (3) imply not (1): if mental states cause physical states but all physical states have complete physical causes, then mental states are physical states and the principle of mind-body duality is false (this is the position of materialistic monism or psychophysical identity theory)
To solve the mind-body problem, one must therefore abandon one of the three statements, thus removing the contradiction that they generate when they are taken simultaneously.
It is on the apparent observation that body and mind differ (1) and that they interact together (2) that lies the historical starting point of the mind-body problem. The main theoretical obstacle to understanding this interaction is that of the “causal completeness” of the physical domain, also called “physical completeness” (3): if physical processes, such as those that take place in our body or our brain, do not have only physical causes or effects, then they cannot have properly mental causes or effects on the spirit. This difficulty in conceiving the interaction between the body and the mind initially constituted the heart of the problem faced by philosophers of the mind since René Descartes.
Today, the mind-body problem is often equated with the difficulties which arise when one tries to explain the relations which exist between the physical states occurring in the brain and the mental states relating to consciousness. Nevertheless, the mind-body problem covers a broader field of questioning than that corresponding to the “difficult problem of consciousness”, a problem which concerns only the subjective and qualitative aspects of experience, and it should therefore not be confused with it. It also raises the essential question of the normative character of the mind and the actions associated with it.
The difficult problem of consciousness
It is to the Australian philosopher David Chalmers that we owe the expression “hard problem of consciousness”, which he distinguishes from “easy problems” relating to the functioning of the mind – problems which are technically complex, but the resolution of which does not pose such epistemological difficulties that one might doubt the possibility of resolving them. These problems are easy, not because they are amenable to simple solutions, but because their solutions require only the specification of the mechanisms which can carry out the various functions of consciousness. The difficult problem of consciousness has the characteristic of persisting even if all the functions in question are explained, because it targets the very nature of conscious states in their phenomenal dimension (phenomenal consciousness). Unlike the cognitive functions of the mind which are involved in language or memory, for example, phenomenal consciousness indeed seems inexplicable in terms of neurophysiological processes, and its properties, irreducible to physical properties as we conceive them today. While we can hope for progress in understanding the mechanisms of the mind thanks to the various sciences dealing with the mind – cognitive sciences, behavioral sciences, neurosciences, etc. – solving the difficult problem of consciousness requires, according to Chalmers, a fundamental theory that integrates phenomenal consciousness. The development of such a theory itself involves a specific research program.
The difficult problem of consciousness is related to the “explanatory gap” as defined by Joseph Levine. The gap in question, of an epistemological order, is that which separates the physicalist understanding of the world and the qualitative experience that we have of it. To solve the difficult problem of consciousness is to bridge this gap by explaining why some of our mental states manifest qualitative aspects (qualia) of a certain type – the “feel like” of seeing red or feeling pain, for example – when certain physical or functional states occur within us. It is not enough, then, to explain how the physical states to which the qualitative aspects of our mental life refer contribute to the production of behavior or the fixation of beliefs, a task a priori realizable in a physicalist framework; rather, it is the ability to explain the qualitative aspects themselves, and their relation to physical states, that is in question. One way of looking at this gap is to define it negatively as the impossibility of deriving phenomenal truths a priori from physical truths. To affirm this impossibility is to say that there are no relations of implication or logical consequences between them, so that one cannot obtain a satisfactory explanation of the phenomenal states on an explanatory basis of a physical order. However, this point does not imply that phenomenal states are not “in reality” physical states, and that physicalism is ontologically false.
The psychology of common sense
Common sense psychology, or naive psychology (or folk psychology) refers to the set of mental concepts that we use to interpret the expressions and actions of our fellow human beings. For example, we commonly interpret behavior as the result of a person’s beliefs, desires, feelings, and will, but we do not use these concepts to understand the motions of an object (such as a ball rolling down a slope). Common sense psychology has a rich vocabulary of mental or psychological terms – “beliefs”, “desires”, “intentions”, “sensory experiences”, “emotions”, etc. – which allow us to describe our fellow human beings and give meaning to their actions. The use of these terms obeys a set of rules or precepts, explicit or implicit, which seems to constitute a kind of theory whose validity would depend essentially on its capacity to predict the behavior of others. Although rudimentary to a certain extent, when compared to scientific psychology, common sense psychology has significant predictive power. Moreover, certain concepts of scientific psychology (memory, attention, etc.) are directly derived from pre-scientific notions of naïve psychology.
The status of the concepts of common sense psychology is today the subject of numerous debates in philosophy of mind, in particular concerning the existence and the nature (physical or strictly mental) of the states or mental processes that they are meant to designate. For some philosophers of mind, such as Paul and Patricia Churchland, such concepts must eventually be “eliminated” (so-called eliminativism) from scientific discourse. According to them, naive psychology constitutes, like other pre-scientific conceptions, a fully developed theory of human behavior, although it is not formalized. It is the last of the popular theories to survive and must suffer the same fate as naive physics or intuitive biology: its replacement by a theory that fits better with current standards of scientificity. The Churchlands insist in particular on the purely fictitious character of intentional states, which the development of the neurosciences will reveal in the same way as that of physics once revealed the chimerical character of alchemical essences, ether or phlogiston.
The idea that the common vocabulary we use to refer to mental states is psychological theory comes from a highly influential essay by American philosopher Wilfrid Sellars: Empiricism and the Philosophy of Mind, published in 1956. According to Sellars, we rely on some sort of theory or proto-theory to explain and predict “rational” behavior, the behavior of an “agent” whose speech and actions are motivated by “reasons”. This theoretical framework forms the background for our psychological analyses, interpretations and explanations of the behavior of others, so that one can speak of a “naive theory of mind”, or a “naive psychology”, spontaneously adopted by each of us after some learning. Such psychology involves specific theoretical postulates and generalizations which take the form of laws. A typical example of such generalizations is the following practical syllogism:
- If X desires A and believes that the best way to get A is to achieve B, then X will desire to achieve B.
Sellars considers the generalizations of naïve psychology to be comparable to the laws and generalizations of the most successful scientific theories, although they are much more informal than those of scientific theories. The entities whose existence is postulated are then the mental states to which we refer daily in our naive understanding of the behavior of others (beliefs, desires, sensations, emotions, etc.). A number of properties are commonly attributed to these theoretical entities, including causal powers, semantic characteristics or qualitative aspects. If they are never directly observed, not even in us, contrary to what our naive epistemology of the mind supposes, the states postulated by the psychology of common sense can nevertheless account with a certain effectiveness for the observable effects at the level of the behavior.
Translated from Wikipedia