Kim's philosophical work focuses on the areas of
philosophy of mind,
metaphysics,
action theory,
epistemology, and
philosophy of science.
Philosophy of mind Kim has defended various
mind-body theories during his career. He began defending a version of the
identity theory in the early 1970s, and then moved to a
non-reductive version of
physicalism, which relied heavily on the
supervenience relation. Kim eventually rejected strict physicalism on the grounds that it provided an insufficient basis for resolving the
mind-body problem. In particular, he concluded that the
hard problem of consciousness—according to which a detailed and comprehensive
neurophysical description of the brain would still not account for the fact of
consciousness—is insurmountable in the context of a thoroughgoing physicalism. His arguments against physicalism can be found in his two latest monographs:
Mind in a Physical World (1998) and
Physicalism, or Something Near Enough (2005). Kim claims "that physicalism will not be able to survive intact and in its entirety." This, according to Kim, is because
qualia (the phenomenal or qualitative aspect of mental states) cannot be reduced to physical states or processes. Kim claims that "phenomenal mental properties are not functionally definable and hence functionally irreducible" and "if functional reduction doesn't work for qualia, nothing will." As of March, 2008, Kim still saw physicalism to be the most comprehensive worldview that is irreplaceable with any other world view. In a 2008 interview with Korean daily newspaper
Joongang Ilbo, Kim stated that we must seek a
naturalistic explanation for mind because mind is a natural phenomenon, and
supernatural explanation only provides "one riddle over another". Kim has raised an objection based on
causal closure and
overdetermination to
non-reductive physicalism. The non-reductive physicalist is committed to following three principles: the
irreducibility of the mental to the physical, some version of mental-physical
supervenience, and the causal
efficaciousness of mental states. The problem, according to Kim, is that when these three commitments are combined with a few other well-accepted principles, an inconsistency is generated that entails the causal impotence of mental properties. The first principle, which most
ontological physicalists would accept, is the causal closure of the physical domain, according to which, every physical effect has a sufficient physical cause. The second principle Kim notes is that of causal exclusion, which holds that no normal event can have more than one sufficient cause. The problem is that a behavior cannot have as its cause, both a physical event and a (supervening) mental event, without resulting in a case of overdetermination (thus violating the principle of causal exclusion). The result is that physical causes exclude mental states from causally contributing to the behavior. In detail: he proposes (using the chart on the right) that
M1 causes
M2 (these are mental events) and
P1 causes
P2 (these are physical events).
M1 has
P1 as its supervenience base, and
M2 has
P2 as its supervenience base. The only way for
M1 to cause
M2, is by causing its supervenience base
P2 (a case of mental-to-physical causation). If
P1 causes
P2, and
M1 causes
P2, then we have a case of causal overdetermination. Applying the principle of causal-exclusion, either
P1 or
M1 must be eliminated as a cause of
P2. Given the principle of the causal closure of the physical domain,
M1 is excluded. The non-reductive physicalist is forced to choose between two unappealing options: one could reject the causal-exclusion principle and claim that in this scenario we are dealing with a genuine case of overdetermination, or one could embrace
epiphenomenalism. Kim argues that mental causation can only be preserved by rejecting the premise of irreducibility in favor of
reduction; in order for mental properties to be considered causally efficacious, they must be reducible to physical properties.
Metaphysics Kim's work in
metaphysics focuses primarily on events and properties. Kim developed an
event identity theory, but has not defended it recently. This theory holds that events are identical if and only if they occur in the same time and place and instantiate the same property. Thus if one waves ten fingers, several events occur, including the waving of an even number of fingers, the event of waving fingers that are evenly divisible by five, and evenly divisible by ten. Some have criticized his theory as producing too many events. Kim also theorized that events are structured. He is known for a property-exemplification account of events. They are composed of three things: Object(s), a property and time or a
temporal interval. Events are defined using the operation [x, P, t]. A unique event is defined by two principles: the existence condition and the identity condition. The existence condition states "[x, P, t] exists if and only if object x exemplifies the n-adic P at time t". This means a unique event exists if the above is met. The identity condition states "[x, P, t] is [y, Q, t`] if and only if x=y, P=Q and t=t`".
Epistemology Kim is a critic of the
naturalized epistemology popularized by
Willard Van Orman Quine in the latter half of the twentieth century. Kim's influential article "What is 'Naturalized Epistemology'?" (1988) argues that "naturalized" epistemologies like Quine's are not proper epistemologies as they are merely descriptive in
scope, while one generally expects an "epistemology" to make
normative claims about
knowledge. Kim argues that mere description of belief-forming practices cannot account for justified belief. (He also argues that to even individuate beliefs, the naturalized epistemologist must presuppose normative criteria of
justification.) Naturalized epistemology cannot address the issue of justification, and therefore it does not share the same aspiration as the traditional approach to epistemology. ==Awards==