Professor dr. J. J. MeyerMenno Lievers
WHAT IS THINKING?Conceptual problem?Empirical problem?What is the task of philosophy?Is philosophy a science?
Conceptual problem?Solution: conceptual analysis (Bennett &
Hacker)
Empirical problem?
No point in doing philosophy. Do research!
The problemJonathan Bennett, Rationality (1964!)Honey-bees
Descartes (1596-1650)Dualism of mind and bodyExtension is the essence of bodyThinking is the essence of mind
Descartes on thoughtThinking occurs with the aid of ideas
(Language of thought…)Ideas are innate (inborn)Methodological solipsism - one can describe
what a subject thinks by taking into account the thinking subject in isolation from his/her environment
Epistemological internalism: a subject can only be said to know that P, iff she can justify P
Locke (1632 - 1704)No innate ideas (à la connectionism…)Thinking is a mental act, not the essence of
the mindThinking requires perception
Kant (1724 - 1804)Synthesis of Descartes and Locke‘Thoughts without content are empty;
intuitions without concepts are blind.’Copernican turn: the way we perceive reality
is a product of our thoughts (thus Harnad’s grounding problem…)
Frege (1848 - 1925)Linguïstic idealism: the way we perceive
reality is a product of our languageThoughts are linguistic
Dummett (1925 - )The Basic Tenet of Analytical PhilosophyAn account of language does not
presuppose an account of thoughtAn account of language yields an account
of thoughtThere is no other adequate means by
which an account of thought may be given
Thoughts are linguisticThe structure of our thoughts equals the
structure of sentences of our languageThe normative rule we ought follow in
thinking are the rules of our languageThinking obeys the rules of logic‘What is meaning?’ becomes the central
question in philosophy.
What is meaning?Meaning resides in your head (Descartes,
Locke)Meaning is a relation between words and
things in reality
Putnam’s Twin-earthEarth: water is H2OTwin-earth: water is XYZWhat is the meaning of ‘water’?What do twins think about?Semantic externalism
ExternalismSemantic externalism: after having been
baptized reality determines whether a word has been used correctly or not
Externalism in the philosophy of mind: the content of thoughts is determined by the environment of the thinker
Epistemological externalism: we can attribute possession of knowledge that P to a subject whether she can justify P or not
The ontology of the mindDualismMaterialism
Advantages of dualismFree willRationality and normativityCreativityInner experienceQualitative aspects of perception
Objections to dualismCausal interaction between body and mindMental causation?What is a mental substance?
MaterialismIdentitytheoryGrandma’s neuronPain = the firing of C-fibersLeibniz’s Law:
(x)((x=y)-->(F)(Fx<-->Fy))
Token-token materialismMultiple realisibilitySupervenienceEmergence
Putnam’s machine functionalismTuring machineFunctional descriptionIdentity mental state determined by input,
relations with other mental states, and outputAntireductionism: psychology remains an
autonomous science
Problems for functionalismQualiaChinese room Inverted spectrumAbsent qualiaChinese people (functional characterization
of mental states too wide)
Develoments after functionalismComputational model of thoughtsLanguage of thought hypothesisModularity of mindRise of subpersonal psychology
ModulesDomainspecificMandatory operationLimited central accessInput systems are fastShallow outputTypical diseaseprocessesInformationally encapsulatedSpecific neural structure
Rise subpersonal psychologySubdoxastic statesModulesImplicit knowledge
Back to meaningTheory of meaning is a theory of
understandingConsequence: Philosophy of language is
imbedded in the philosophy of mindMeaning is being analysed as a ‘way of
thinking’
Gareth EvansExternalismGenerality constraint: you can only attribute
to a thinking subject possession of the concept F, if and only if he or she cannot only entertain the thought that Fa, but also that Fb
Non-conceptual content
Back to ontology:eliminative materialismScientific realismImpossibility of inter-theoretical reductionTheory-ladenness of perceptionMeaning-holismFolk-psychology is a false theory
Consequences for AI:1. Symbol System HypothesisEmploy a rich, recursive compositional
language to represent realityBuild an adequate representation of
reality within a universal symbol systemUse input to construct representations of
the environment in response to stimuliProcess input (possibly into output)Output is a symbolic representation of
adequate, suitable responses to the input
Philosophical presuppositions of the SSHInternalismToken-token materialism?Thinking is symbolmanipulationInnate representations?Methodological dualismThinking normative/logical?
Connectionist systems
Connectionist systemsAdaptive (empirism)Thoughts are not propositional
(compositional)Externalism?Normativity of thinking?Biologically real?No innate mental properties/knowledge?
AI versus NeurofilosofieIntelligence is a biological phenomenonRepresentation is a product of our biological
constitutionBiological materialism‘Hard’ AI presupposes supervenience and
that is nonsense
COURSE SET-UPMAPPING GREAT DEBATES:
CAN COMPUTERS THINK?
WEB-SITE: http://www.macrovu.com/CCTGeneralInfo.html
SEVEN QUESTIONS1. CAN COMPUTERS THINK?
SEVEN QUESTIONS1. CAN COMPUTERS THINK?2. CAN THE TURING-TEST DETERMINE
WHETHER COMPUTERS CAN THINK?
SEVEN QUESTIONS1. CAN COMPUTERS THINK?2. CAN THE TURING-TEST DETERMINE
WHETHER COMPUTERS CAN THINK?3. CAN PHYSICAL SYMBOL SYSTEMS
THINK?
SEVEN QUESTIONS1. CAN COMPUTERS THINK?2. CAN THE TURING-TEST DETERMINE
WHETHER COMPUTERS CAN THINK?3. CAN PHYSICAL SYMBOL SYSTEMS
THINK?4. CAN CHINESE ROOMS THINK?
SEVEN QUESTIONS1. CAN COMPUTERS THINK?2. CAN THE TURING-TEST DETERMINE
WHETHER COMPUTERS CAN THINK?3. CAN PHYSICAL SYMBOL SYSTEMS
THINK?4. CAN CHINESE ROOMS THINK?
SEVEN QUESTIONS5’. CAN CONNECTIONIST NETWORKS
THINK?
SEVEN QUESTIONS5’. CAN CONNECTIONIST NETWORKS
THINK?5’’.CAN COMPUTERS THINK IN IMAGES?
SEVEN QUESTIONS5’. CAN CONNECTIONIST NETWORKS
THINK?5’’.CAN COMPUTERS THINK IN IMAGES?6. DO COMPUTERS HAVE TO BE CONSCIOUS
TO THINK?
SEVEN QUESTIONS5’. CAN CONNECTIONIST NETWORKS
THINK?5’’.CAN COMPUTERS THINK IN IMAGES?6. DO COMPUTERS HAVE TO BE CONSCIOUS
TO THINK?7. ARE THINKING COMPUTERS
MATHEMATICALLY POSSIBLE?