Explanatory gap

Last updated

In the philosophy of mind, the explanatory gap is the difficulty that physicalist philosophies have in explaining how physical properties give rise to the way things feel subjectively when they are experienced. It is a term introduced by philosopher Joseph Levine. [1] In the 1983 paper in which he first used the term, he used as an example the sentence, "Pain is the firing of C fibers", pointing out that while it might be valid in a physiological sense, it does not help us to understand how pain feels.

Contents

The explanatory gap has vexed and intrigued philosophers and AI researchers alike for decades and caused considerable debate. Bridging this gap (that is, finding a satisfying mechanistic explanation for experience and qualia) is known as "the hard problem". [2] The hardness of the problem is such that mysterians believe it can never be solved by humans. Ned Block argues that there also exists a "harder problem" of consciousness, due to the possibility of different physical and functional neurological systems potentially having phenomenal overlap. [3]

An example of a phenomenon in which there is no gap is a modern computer's behavior, which can be adequately explained by its physical components alone, such as its circuitry and software. [4] In contrast, it is thought by many mind-body dualists (e.g. René Descartes, David Chalmers) that subjective conscious experience constitutes a separate effect that demands another cause that is either outside the physical world (dualism) or due to an as yet unknown physical phenomenon (see for instance quantum mind, indirect realism).

Proponents of dualism claim that the mind is substantially and qualitatively different from the brain and that the existence of something metaphysically extra-physical is required to "fill the gap". Similarly, some argue that there are further facts—facts that do not follow logically from the physical facts of the world—about conscious experience. For example, they argue that what it is like to experience seeing red does not follow logically from the physical facts of the world.

In addition to the qualities of subjective experiences, the existence of personal identity also poses potential problems for physicalist philosophies. The question of why an individual has their particular personal identity has been called the vertiginous question by philosopher Benj Hellie, and has been termed the "Even Harder Problem of Consciousness" by Tim S. Roberts. [5] However, proponents of open individualism may argue that the existence of personal identity is illusory. [6]

Implications

The nature of the explanatory gap is disputed. Some consider it to be simply a limit on our current explanatory ability. [7] They argue that future findings in neuroscience or future work from philosophers could close the gap. Others argue that the gap is a definite limit on our cognitive abilities as humans—no amount of further information will allow us to close it. [8] There is no consensus about what metaphysical conclusions the existence of the gap provides. Those who use its existence to support dualism have often taken the position that an epistemic gap—particularly if it is a definite limit on our cognitive abilities—necessarily entails a metaphysical gap. [9]

Joseph Levine[ clarification needed ] and others opt to either remain silent on the matter or argue that no such metaphysical conclusion should be drawn. [1] He agrees that conceivability (as used in the Zombie and inverted spectrum arguments) the theory is flawed as a means of establishing metaphysical realities; but argues that even if we come to the metaphysical conclusion that qualia are physical, they still present an explanatory problem.

While I think this materialist response is right in the end, it does not suffice to put the mind-body problem to rest. Even if conceivability considerations do not establish that the mind is in fact distinct from the body, or that mental properties are metaphysically irreducible to physical properties, still they do demonstrate that we lack an explanation of the mental in terms of the physical. [10]

However, such an epistemological or explanatory problem might indicate an underlying metaphysical issue—the non-physicality of qualia, even if not proven by conceivability arguments, is far from ruled out.

In the end, we are right back where we started. The explanatory gap argument doesn't demonstrate a gap in nature, but a gap in our understanding of nature. Of course, a plausible explanation for there being a gap in our understanding of nature is that there is a genuine gap in nature. But so long as we have countervailing reasons for doubting the latter, we have to look elsewhere for an explanation of the former. [10]

At the core of the problem, according to Levine, is our lack of understanding of what it means for a qualitative experience to be fully comprehended. He emphasizes that we do not even know to what extent it is appropriate to inquire into the nature of this kind of experience. He uses the laws of gravity as an example, which laws seem to explain gravity completely yet do not account for the gravitational constant. Similarly to the way in which gravity appears to be an inexplicable brute fact of nature, the case of qualia may be one in which we are either lacking essential information or in which we are exploring a natural phenomenon that simply is not further apprehensible. Levine suggests that for this reason perhaps we should consider whether it is necessary to find a more complete explanation of qualitative experience. [11]

Levine points out that understanding how much there is to be known about qualitative experience seems even more difficult because we lack a way to articulate what it means for actualities to be knowable in the manner that he has in mind. He concludes that there are good reasons to want a more complete explanation of qualitative experiences. One is that consciousness appears to manifest only where mentality is demonstrated in physical systems that are quite highly organized. This, of course, may be indicative of a human capacity for reasoning that is no more than the result of organized functions.[ clarification needed ] Levine argues that it seems counterintuitive to accept this implication that the human brain, so highly organized as it is, could be no more than a routine executor.[ non sequitur ] He notes that while materialism appears to entail reducibility of anything that is not physically primary to an explanation of its dependence on a mechanism that can be described in terms of physical fundamentals, that kind of reductionism does not attempt to reduce psychology to physical science. However, it still entails that there are inexplicable classes of facts which are not treated as relevant to statements pertinent to psychology.[ how? ][ citation needed ]

Christian List believes that the existence of first-personal facts provide a refutation of not only physicalist theories of consciousness, but also most standard versions of dualism. [12]

Many philosophers have doubted that the explanatory gap can be solved. As proponents of the argument use it to support arguments against materialism, physicalism, and naturalism, its arguments appear to resist any scientific or philosophical solution to the problem. David Chalmers acknowledged that even when science bridges the gap to some degree, the problem will persist. [2]

History

Leibniz's passage describing the explanatory gap is as follows:

It must be confessed, moreover, that perception, and that which depends on it, are inexplicable by mechanical causes, that is, by figures and motions, And, supposing that there were a mechanism so constructed as to think, feel and have perception, we might enter it as into a mill. And this granted, we should only find on visiting it, pieces which push one against another, but never anything by which to explain a perception. This must be sought, therefore, in the simple substance, and not in the composite or in the machine.

See also

Related Research Articles

Neutral monism is an umbrella term for a class of metaphysical theories in the philosophy of mind, concerning the relation of mind to matter. These theories take the fundamental nature of reality to be neither mental nor physical; in other words it is "neutral".

In philosophy, physicalism is the view that "everything is physical", that there is "nothing over and above" the physical, or that everything supervenes on the physical. It is opposed to idealism, according to which the world arises from mind. Physicalism is a form of ontological monism—a "one substance" view of the nature of reality, unlike "two-substance" or "many-substance" (pluralism) views. Both the definition of "physical" and the meaning of physicalism have been debated.

<span class="mw-page-title-main">Mind–body dualism</span> Philosophical theory

In the philosophy of mind, mind–body dualism denotes either the view that mental phenomena are non-physical, or that the mind and body are distinct and separable. Thus, it encompasses a set of views about the relationship between mind and matter, as well as between subject and object, and is contrasted with other positions, such as physicalism and enactivism, in the mind–body problem.

In the philosophy of mind, functionalism is the thesis that each and every mental state is constituted solely by its functional role, which means its causal relation to other mental states, sensory inputs, and behavioral outputs. Functionalism developed largely as an alternative to the identity theory of mind and behaviorism.

<span class="mw-page-title-main">David Chalmers</span> Australian philosopher and cognitive scientist

David John Chalmers is an Australian philosopher and cognitive scientist specializing in the areas of the philosophy of mind, and the philosophy of language. He is a professor of philosophy and neural science at New York University, as well as co-director of NYU's Center for Mind, Brain and Consciousness. In 2006, he was elected a Fellow of the Australian Academy of the Humanities. In 2013, he was elected a Fellow of the American Academy of Arts & Sciences.

Eliminative materialism is a materialist position in the philosophy of mind. It is the idea that the majority of mental states in folk psychology do not exist. Some supporters of eliminativism argue that no coherent neural basis will be found for many everyday psychological concepts such as belief or desire, since they are poorly defined. The argument is that psychological concepts of behavior and experience should be judged by how well they reduce to the biological level. Other versions entail the nonexistence of conscious mental states such as pain and visual perceptions.

The knowledge argument is a philosophical thought experiment proposed by Frank Jackson in his article "Epiphenomenal Qualia" (1982) and extended in "What Mary Didn't Know" (1986).

<span class="mw-page-title-main">Panpsychism</span> View that mind is a fundamental feature of reality

In the philosophy of mind, panpsychism is the view that the mind or a mind-like aspect is a fundamental and ubiquitous feature of reality. It is also described as a theory that "the mind is a fundamental feature of the world which exists throughout the universe". It is one of the oldest philosophical theories, and has been ascribed to philosophers including Thales, Plato, Spinoza, Leibniz, William James, Alfred North Whitehead, Bertrand Russell, and Galen Strawson. In the 19th century, panpsychism was the default philosophy of mind in Western thought, but it saw a decline in the mid-20th century with the rise of logical positivism. Recent interest in the hard problem of consciousness, and developments in the fields of neuroscience, psychology, and quantum mechanics have revived interest in panpsychism in the 21st century.

<span class="mw-page-title-main">Hard problem of consciousness</span> Philosophical concept

In the philosophy of mind, the hard problem of consciousness is to explain why and how humans and other organisms have qualia, phenomenal consciousness, or subjective experience. It is contrasted with the "easy problems" of explaining why and how physical systems give a (healthy) human being the ability to discriminate, to integrate information, and to perform behavioral functions such as watching, listening, speaking, and so forth. The easy problems are amenable to functional explanation—that is, explanations that are mechanistic or behavioral—since each physical system can be explained purely by reference to the "structure and dynamics" that underpin the phenomenon.

A philosophical zombie is a being in a thought experiment in the philosophy of mind that is physically identical to a normal human being but does not have conscious experience.

The inverted spectrum is the hypothetical concept, pertaining to the philosophy of color, of two people sharing their color vocabulary and discriminations, although the colors one sees—one's qualia—are systematically different from the colors the other person sees.

Jaegwon Kim was a Korean-American philosopher. At the time of his death, Kim was an emeritus professor of philosophy at Brown University. He also taught at several other leading American universities during his lifetime, including the University of Michigan, Cornell University, the University of Notre Dame, Johns Hopkins University, and Swarthmore College. He is best known for his work on mental causation, the mind-body problem and the metaphysics of supervenience and events. Key themes in his work include: a rejection of Cartesian metaphysics, the limitations of strict psychophysical identity, supervenience, and the individuation of events. Kim's work on these and other contemporary metaphysical and epistemological issues is well represented by the papers collected in Supervenience and Mind: Selected Philosophical Essays (1993).

Type physicalism is a physicalist theory in the philosophy of mind. It asserts that mental events can be grouped into types, and can then be correlated with types of physical events in the brain. For example, one type of mental event, such as "mental pains" will, presumably, turn out to be describing one type of physical event.

In philosophy, a theory of everything (ToE) is an ultimate, all-encompassing explanation or description of nature or reality. Adopting the term from physics, where the search for a theory of everything is ongoing, philosophers have discussed the viability of the concept and analyzed its properties and implications. Among the questions to be addressed by a philosophical theory of everything are: "Why is reality understandable?" – "Why are the laws of nature as they are?" – "Why is there anything at all?"

The philosophy of mind is a branch of philosophy that deals with the nature of the mind and its relation to the body and the external world.

<span class="mw-page-title-main">What Is It Like to Be a Bat?</span> 1974 philosophy paper by Thomas Nagel

"What Is It Like to Be a Bat?" is a paper by American philosopher Thomas Nagel, first published in The Philosophical Review in October 1974, and later in Nagel's Mortal Questions (1979). The paper presents several difficulties posed by phenomenal consciousness, including the potential insolubility of the mind–body problem owing to "facts beyond the reach of human concepts", the limits of objectivity and reductionism, the "phenomenological features" of subjective experience, the limits of human imagination, and what it means to be a particular, conscious thing.

<span class="mw-page-title-main">Qualia</span> Instances of subjective experience

In philosophy of mind, qualia are defined as instances of subjective, conscious experience. The term qualia derives from the Latin neuter plural form (qualia) of the Latin adjective quālis meaning "of what sort" or "of what kind" in relation to a specific instance, such as "what it is like to taste a specific apple — this particular apple now".

<i>The Conscious Mind</i> 1996 philosophy book by David Chalmers

The Conscious Mind: In Search of a Fundamental Theory was published in 1996, and is the first book written by David Chalmers, an Australian philosopher specialising in philosophy of mind. Although the book has been greatly influential, Chalmers maintains that it is "far from perfect", as most of it was written as part of his PhD dissertation after "studying philosophy for only four years".

Joseph Levine is an American philosopher at the University of Massachusetts Amherst who received his PhD from Harvard University in 1981.

The phenomenal concept strategy (PCS) is an approach within philosophy of mind to provide a physicalist response to anti-physicalist arguments like the explanatory gap and philosophical zombies. The name was coined by Daniel Stoljar. As David Chalmers put it, PCS "locates the gap in the relationship between our concepts of physical processes and our concepts of consciousness, rather than in the relationship between physical processes and consciousness themselves." The idea is that if we can explain why we think there is an explanatory gap, this will defuse the motivation to question physicalism.

References

  1. 1 2 Levine, J. 1983. “Materialism and qualia: the explanatory gap”. Pacific Philosophical Quarterly, 64: 354–361.
  2. 1 2 David Chalmers, Facing Up to the Problem of Consciousness, JCS, 2 (3), 1995 Archived 2011-05-14 at the Wayback Machine , pp. 200–19.
  3. Block, Ned (2002). "The Harder Problem of Consciousness". The Journal of Philosophy. 99 (8): 391–425. doi:10.2307/3655621. JSTOR   3655621. S2CID   111383062.
  4. "CHAPTER 4: MIND AND BODY". www.utm.edu. Retrieved 15 March 2022.
  5. Roberts, Tim S. (September 2007). "The Even Harder Problem of Consciousness by Roberts. Tim S." NeuroQuantology. 5 (2): 214–221. doi:10.14704/nq.2007.5.2.129.
  6. Kolak, Daniel (2007-11-03). I Am You: The Metaphysical Foundations for Global Ethics. Springer Science & Business Media. ISBN   978-1-4020-3014-7.
  7. Dennett, D. C. 1991. Consciousness Explained. Boston: Little, Brown and Company.
  8. McGinn, C. 1989. “Can we solve the mind-body problem?” Mind, 98: 349–66
  9. Chalmers, D. 1996. The Conscious Mind. Oxford: Oxford University Press.
  10. 1 2 J. Levine, "Conceivability, Identity, and the Explanatory Gap" in Stuart R. Hameroff, Alfred W. Kaszniak and David Chalmers (eds.), Towards a Science of Consciousness III: The Third Tucson Discussions and Debates, The MIT Press, 1999, pp 3–12.
  11. Levin, Janet (2002). "Is Conceptual Analysis Needed for the Reduction of Qualitative States?". Philosophy and Phenomenological Research. 64 (3): 571–591. doi:10.1111/j.1933-1592.2002.tb00161.x. ISSN   0031-8205. JSTOR   3070969 . Retrieved 15 March 2022.
  12. List, Christian (2023). "A quadrilemma for theories of consciousness". The Philosophical Quarterly. Retrieved 3 September 2024.