Philosophy of Mind: A Functionalist Primer

An excerpt from the online hypertext Human Knowledge: Foundations and Limits.

Philosophy Of Mind: the study of the faculty for thinking and knowing.

  1. Essence of Mind.
  2. Accidence of Mind.
  3. Relations of Mind.
Minds and ideas, like all of reality, consist ultimately of matter.  Mental states are functional states consisting of causal relations among components for processing information.
Theories of Mind
 Philosophers often divide all phenomena into three kinds: Human theories of mind differ according to how they explain these phenomena in general and the Mind-Body Problem in particular.  The Mind-Body Problem is the problem of explaining how mindless unconscious matter can give rise to or interact with mind and consciousness.  Human theories of mind include: Idealism is incorrect because its explanation of matter is either inadequate or unparsimonious.  Dualism is incorrect because it unparsimoniously posits a realm of the ideal.  Logical Behaviorism is unsatisfactory because behavioral explanations are too unwieldy.  Identity Theory is incorrect because it holds that the essence of mind is its construction instead of its function. Philosophy / Epistemology / Philosophy Of Mind / Essence of Mind

mind is any volitional conscious faculty for perception and cognition.
Cognition is the process of learning, reasoning, and knowingLearning is the processing of experience into an increase in knowledge or behavioral effectiveness. Reasoning is the process of making and evaluating valid inferences.
Perception is the process of organizing sensation into experienceSensation is the process of external influence on a monitoring or control system. Experience is any relatively unified and coherent interpretation of related contemporaneous sensations.
Consciousness is awareness of self and environment. Awareness is the direct and central availability of information in a monitoring or control system.
Volition is the power or act of making decisions about an agent's own actions.  A decision is the causing by a system of events which were not physically determined from outside the system but rather were at least somewhat contingent on the internals of the system, and which were not predictable except perhaps by modeling the internals of the system.

Free will is either of the doctrines that human choices are a) determined internally rather than externally (volitional free will) or b) not pre-determined at all (indeterminate free will).  Determinism is incompatible with indeterminate free will, but is compatible with volitional free will if agents have internal state that influences (and thus helps determines) their actions.  Volitional free will is also compatible with forms of indeterminism in which the acausality is not so rampant as to undermine agent self-influence.  Indeterminate free will requires indeterminism, but degenerates into uncaused chance if acausality confounds not only prediction of effect but also attribution of cause.

Since most effects seem caused rather than uncaused, and since the complexity of minds makes them hard to predict, minds appear to have at least weak free will. Weak free will is sufficient for assigning ethical responsibility to decision-making systems even in the face of complete determinism.

Do minds have strong free will, or can their decisions in principle be inferred from sufficient knowledge of prior circumstances?

Anti-materialists posit an immaterial soul or will that is free from both deterministic causality and random acausality. This notion violates the law of the excluded middle. Either the immaterial will is subject to (perhaps probabilistic but nonetheless causal) causes, or it is not. The same is true of material minds. The actions of an immaterial will could be said to be caused by its own internal causal processes, but the same can be said of material minds. Philosophy / Epistemology / Philosophy Of Mind / Accidence of Mind

Non-essential but perhaps inevitable aspects of mind include subjectivity, intentionality, and affect.
Objectivity is independence from a point of view or perspective that is inherently private. Subjectivity is dependency on a point of view or perspective that is inherently private. Subjective experience is the private phenomenal aspect of experience, the vivid feeling of what an experience is "like".

Subjective experience consists of complex associations among perceptions, and necessarily occurs in systems having such associations.  If a subjective experience is not "like" anything (i.e. not associated with any other perceptions), it is not a subjective experience at all.

Physicalism is the thesis that all facts can be described in physical (and thus non-subjective) terms. Some humans have what they call a "natural belief that collections of cells do not generate minds" [McGinn 1999] and that therefore physicalism must be false.

Such a belief seems only as "natural" as the belief that collections of atoms do not generate life, and just as unjustified. The operation of e.g. the human brain does not mysteriously cause consciousness, but rather it simply constitutes consciousness.

Qualia are ineffable intrinsic subjective qualities of perception, such as the redness of red, beyond the functional or dispositional properties of perception. Qualia are taken by opponents of physicalism to be a mysterious phenomenon that physicalism cannot explain.

However, qualia do not exist, because the functional and dispositional properties of perception can, in fact, explain the subjective qualities of perception. The functional role of certain sorts of perceptions in a conscious system necessarily and understandably entails that the system will report qualia. Thus there are no ineffable intrinsic subjective qualities of perception beyond its functional qualities.

The Knowledge Argument is an argument made by Frank Jackson in 1982 purporting to show that physicalism is false because knowledge of all the relevant physical facts does not include, for certain experiences such as the redness of red, knowledge of what it is like to have them before they are had. Jackson hypothesizes in the distant future a brilliant neuroscientist Mary spending her whole life in a colorless room learning all the physical facts about seeing the color red.  Jackson claims that only when Mary sees something red can she learns the new fact of what redness is like, and that therefore physicalism is false.

Jackson's argument fails because it ignores the difference between memorizing an algorithm and executing it.  The experience of the redness of red consists in the operation of a complex set of functional components for processing information.  While we can conceive of Mary having serial access to arbitrarily many memorized facts about such components, we cannot conceive of her having a large enough working memory or a fast enough mind to "manually" perform the operations "in her head" in order to recreate the experience of redness. Similarly, Mary could memorize the sequence of pixels in a monochrome bitmap and yet still not be able to mentally visualize what the bitmap will look like -- even if it is an image of a favorite drawing which she had already memorized in arbitrary detail.

zombie is a hypothetical creature that is stipulated to lack subjective experience but is behaviorally and physically indistinguishable from a human. The conceivability or logical possibility of zombies is taken by opponents of physicalism to show that physicalism is false.

It seems impossible to conceive of a creature that lacks subjective experience but nevertheless exhibits all the self-reporting behaviors of humans that help us to ascribe subjective experience to them.  Therefore, zombies are inconceivable and do not show physicalism to be false.

Intentionality is aboutness -- the property of being about, directed at, or suited for.

A system has intentionality by virtue of its potential and actual causal relations with the world.

The Chinese Room is a thought experiment devised by John Searle in 1980 to show that there cannot be intentionality or understanding in a formal symbol manipulation system such as a room in which a speaker of English manually executes an algorithm allowing the room to pass the Turing Test in Chinese. Searle claims that intentionality "is a biological phenomenon, and it is as likely to be as causally dependent on the specific biochemistry of its origins as lactation [or] photosynthesis". Searle charges that functionalism is a form of dualism because it says mind is in principle independent of the specific biochemistry of the brain.

The human in the Chinese Room does not understand Chinese, but the human running the algorithm implements a system that does indeed understand Chinese. The system has intentionality by virtue of the causal relations that allow it to correctly answer questions posed to it in Chinese. Intentionality is a formal or informational property, whereas lactation and photosynthesis involve chemistry and energy. Simulated thinking can indeed produce understanding, just as simulated musical composition can indeed produce a sonata. If a functional explanation of mind is "dualistic", then so is a functional explanation of long division or carburetion.

Affect is a general and often undirected negative or positive attitude, beyond overall sensory or cognitive state, that influences motive and colors perception. Is affect indeed an inevitable attribute of any volitional system with complex motives? Philosophy / Epistemology / Philosophy Of Mind / Relations of Mind

Mind and Object
Concepts are abstractions induced by minds from instances. Concepts are the products of
the not-fully-understood facility by which a mind induces general properties from instances, and are themselves the not-fully-understood facility by which a mind recognizes those general properties in other similar instances.Ideas are conceptsUniversals are kinds or categories of terms that are related according to shared properties. Human theories about universals are of three general kinds: Universals do not exist independently of the instances that instantiate them and the minds that conceptualize them.
Mind and Minds
The Other Minds Problem is the problem of ascertaining whether external realty and other minds actually exist or merely appear to exist. Solipsism is the thesis that external reality and other minds do not actually exist. Solipsism incorrectly concludes not-X simply because X cannot be known with absolute certainty, and thus ignores the preferred conclusion of probably-X.
Mind and Identity
A mind is identical with its closest close-enough continuous-enough continuer.  Processes that preserve mental (and thus personal) identity include: By contrast, the following processes do not preserve identity, usually because of being not continuous or not continuous-enough: It is perhaps logically possible for a single mind to fission continuously into more than one, or for more than one to continuously fuse into one, with identity being preserved in both cases. Chaotic or quantum effects probably make such fission or fusion physically impossible, since they might make it impossible to precisely synchronize the functioning of the duplicate components during the transition.
Mind and Spacetime
As noted by Dennett, the subjective sense of here -- the observer's spatial location -- is fixed by the content of mental events, and not by their spatial location. The subjective sense of now -- the observer's temporal location -- is similarly fixed by the content of mental events, and not by their temporal location.

Materialism implies that consciousness is distributed over space and time in a material substrate of mind such as the human brain. Thus there is no moment in time or point in space at which a thought enters consciousness.  Asking when precisely did a material mind become conscious of an event is like asking when precisely did the British Empire learn of the signing of the treaty that ended the War of 1812.  (The Battle of New Orleans was fought two weeks after the treaty was signed, by soldiers that had not yet heard of the signing.)

Mind and Artifact
Functionalism implies that, in principle, an artificial mind is possible, and that therefore a machine could think.

TheTuring Test is an assay for intelligence in which an interrogator using teletyped queries attempts to distinguish between a certified intelligence and a candidate intelligence. A rigorous interrogator can pose lines of questioning that can only be answered by use of the perceptive inductions that are the essence of intelligence. Not every intelligence could pass such a rigorous Turing Test, but everything that passes such a Turing Test is an intelligence.

Roger Penrose argues that the human mind is not computable because, given a formalization of one's mind and the Godel sentence for one's mind, a human mind allegedly could recognize the sentence as true whereas the formalized computation could not. Penrose errs in assuming one could know a formalization of one's mind and correctly believe in its consistency. Godel's Theorem merely shows that any formalizable reasoning faculty could not correctly believe in its own consistency.

Mind and Supermind
These are some of the levels of information-processing ability: Automentation can be superior to regular intelligence in efficiency, flexibility, speed, capacity, bandwidth, and network associativity, but not in cognition. There are no forms of reasoning or kinds of knowledge that are in principle inaccessible to regular intelligence.
Mind and Limits
There are several ways in which minds are limited in theory and in practice.