In the
philosophy of mind and
consciousness, the explanatory gap is the proposed 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.
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.
The explanatory gap has vexed and intrigued
philosopher
A philosopher is a person who practices or investigates philosophy. The term ''philosopher'' comes from the grc, φιλόσοφος, , translit=philosophos, meaning 'lover of wisdom'. The coining of the term has been attributed to the Greek th ...
s 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".
[ David Chalmers]
''Facing Up to the Problem of Consciousness''
, pp. 200-19.
To take an example of a phenomenon in which there is no gap, a modern computer's behavior can be adequately explained by its physical components alone, such as its circuitry and software. 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
Dualism most commonly refers to:
* Mind–body dualism, a philosophical view which holds that mental phenomena are, at least in certain respects, not physical phenomena, or that the mind and the body are distinct and separable from one another
** ...
claim that the
mind
The mind is the set of faculties responsible for all mental phenomena. Often the term is also identified with the phenomena themselves. These faculties include thought, imagination, memory, will, and sensation. They are responsible for various m ...
is substantially and qualitatively different from the
brain and that the existence of something
metaphysically
Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of consci ...
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.
Implications
The nature of the explanatory gap has been the subject of some debate. For example, some consider it to simply be a limit on our current explanatory ability. They argue that future findings in neuroscience or future work from philosophers could close the gap. However, others have taken a stronger position and argued that the gap is a definite limit on our cognitive abilities as humans—no amount of further information will allow us to close it. There has also been no consensus regarding what metaphysical conclusions the existence of the gap provides. Those wishing to 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.
Levine and others have wished to either remain silent on the matter or argue that no such metaphysical conclusion should be drawn.
[Levine, J. 1983. “Materialism and qualia: the explanatory gap”. Pacific Philosophical Quarterly, 64: 354-361.] He agrees that conceivability (as used in the
Zombie and
inverted spectrum 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 t ...
arguments) is flawed as a means of establishing metaphysical realities; but he points out 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.[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.]
However, such an
epistemological
Epistemology (; ), or the theory of knowledge, is the branch of philosophy concerned with knowledge. Epistemology is considered a major subfield of philosophy, along with other major subfields such as ethics, logic, and metaphysics.
Episte ...
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.
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 don't 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're exploring a natural phenomenon that simply is not further apprehensible. Levine suggests that, as qualitative experience of a physical or functional state may simply be such a brute fact, perhaps we should consider whether or not it is really necessary to find a more complete explanation of qualitative experience.
Levine points out that the solution to the problem of understanding how much there is to be known about qualitative experience seems even more difficult because we also lack a way to articulate what it means for actualities to be knowable in the manner that he has in mind. He does conclude that there are good reasons why we wish for a more complete explanation of qualitative experiences. One very significant reason is that consciousness appears to only manifest 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. Levine expresses 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. He notes that although, at minimum, 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 doesn't 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.
Many philosophers have doubted the idea that explanatory gap could be solved, being that proponents of the argument use it to support arguments against materialism, physicalism and naturalism, it’s arguments appear to resist any scientific or philosophical solution to the problem. David Chalmers has also acknowledged that even when science bridges the gap to some degree, the problem will persist.
See also
*
Animal consciousness
Animal consciousness, or animal awareness, is the quality or state of self-awareness within a non-human animal, or of being aware of an external object or something within itself. In humans, consciousness has been defined as: sentience, aware ...
*
Blindsight
*
Causality
Causality (also referred to as causation, or cause and effect) is influence by which one event, process, state, or object (''a'' ''cause'') contributes to the production of another event, process, state, or object (an ''effect'') where the cau ...
*
Consciousness
*
Explanation
*
Functionalism (philosophy of mind)
*
Further facts
*
Ideasthesia
*
Materialism
Materialism is a form of philosophical monism which holds matter to be the fundamental substance in nature, and all things, including mental states and consciousness, are results of material interactions. According to philosophical materiali ...
*
Mind
The mind is the set of faculties responsible for all mental phenomena. Often the term is also identified with the phenomena themselves. These faculties include thought, imagination, memory, will, and sensation. They are responsible for various m ...
*
Mind-body problem
*
Philosophical zombie
*
Philosophy of mind
*
Problem of other minds
*
Qualia
*
Reductionism
Reductionism is any of several related philosophical ideas regarding the associations between phenomena which can be described in terms of other simpler or more fundamental phenomena. It is also described as an intellectual and philosophical pos ...
*
Reverse engineering
Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompli ...
*
Sentience
Sentience is the capacity to experience feelings and sensations. The word was first coined by philosophers in the 1630s for the concept of an ability to feel, derived from Latin '':wikt:sentientem, sentientem'' (a feeling), to distinguish it fro ...
*
Solipsism
*
Turing test
*
Vitalism
Vitalism is a belief that starts from the premise that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things." Wher ...
References
External links
Joseph Levine's homepage"What is it like to be a bat?" Thomas Nagel, ''The Philosophical Review'' LXXXIII, 4 (October 1974): 435–50.
{{Consciousness
Arguments in philosophy of mind
Consciousness studies
Mind–body problem
Philosophical analogies
Philosophy of science