mind. Property dualism combines the thesis that mental phenomena are
strictly irreducible to physical phenomena with the denial that mind
and body are discrete substances. For the anomalous monist, the
plausibility of property dualism derives from the fact that although
mental states, events and processes have genuine causal powers, the
causal relationships that they enter into with physical entities
cannot be explained by appeal to fundamental laws of nature. This
doctrine about the relationship between mind and body was first
explicitly defended by Donald Davidson in his paper "Mental Events,"
though its root in the Western philosophical tradition go back at
least as far as Spinoza. It was a topic of energetic debate and
disagreement among English-speaking philosophers for the last thirty
years of the twentieth century.
1. A Trilemma
Anomalous Monism (AM) is a philosophical thesis about the place of the
mind and of mental states in the natural order. The term was first
used by Donald Davidson in his 1970 paper "Mental Events." Since the
publication of this paper, Davidson has re-described and refined his
position on the mind/body problem in a number of different ways, and
both critics and supporters of AM have come up with their own
characterizations of the thesis, many of which appear to differ from
Davidson's in non-trivial ways. Nonetheless, AM is distinguished from
other positions in the philosophy of mind by the three following
claims:
1. Mental events cause physical events.
2. All causal relationships are backed by natural laws.
3. There are no natural laws connecting mental phenomena with
physical phenomena.
Taken separately, none of these claims has won anything like universal
support from philosophers in the contemporary tradition. So-called
"epiphenomenalists" about the nature of mental events and processes
would certainly deny the truth of (1). (2) appears to require both
denying that the notion of a causal disposition is more primitive than
that of a natural law, as well as affirming an implausibly strict
distinction between genuine laws of nature and mere statistical
generalizations. And proponents of a reductionist view of the mind, at
least as this sort of position has traditionally been articulated,
would certainly have to deny the truth of (3).
Even if none of these arguments are successful, this trio of claims
gives off a pretty strong whiff of inconsistency. Nonetheless,
Davidson maintains that all three are true. The best route to
understanding this is to start out by taking a somewhat broader look
at the relevant historical backdrop. It is also necessary to acquaint
oneself with Davidson's broader philosophical program.
2. Historical Precursors
a. Parallelism
The early modern philosopher whose views on the relationship between
mind and body bear the closest similarity to AM is Benedict De
Spinoza. Like most philosophers of his period, Spinoza was preoccupied
with the central problem of the Cartesian inheritance, namely, that of
accounting for the apparently systematic causal interaction between
mind and body. This problem had arisen for Descartes specifically
because he had believed that mind and body were discrete types of
substances with irreconcilable natures. ContraDescartes, Spinoza
denied that mind and body were separate substances at all, and
proposed instead that they are merely separate attributes of a single
substance. He suggested that, for every physical item P, there is a
corresponding mental item I(P), which he identified as "the idea of
P." The human mind, for example, was nothing for Spinoza but the
"idea" of the human body. These "ideas" differ from one another in
"perfection," based upon the complexity of the physical object to
which each corresponds.
In Book Two of the Ethics, Spinoza goes on to defend (very briefly)
the doctrine of psycho-physical parallelism. He proposes that "the
order and connection of ideas is the same as the order and connection
of things." [de Spinoza, 1949, p. 83] This remark is usually taken to
imply that for every causal chain of ideas, there is a sequence of
physical causes and effects that run parallel to it through time, like
so [see Bennett pp. 127-132]:
t1 t2 t3 t4 t5
Sequence A P1 P2 P3 P4 P5
Sequence B I(P)1 I(P)2 I(P)3 I(P)4 I(P)5
Spinoza showed no obvious sign of interest in whether one of these two
causal orders is more fundamental. But since he was a strict
determinist, it seems he believed that the relations that obtain among
the items belonging to both causal sequences were law-like in nature.
He may thus plausibly be read as having accepted the truth of
something like statement (1).
A further distinctive feature of Spinoza's metaphysical monism,
however, was his denial that there could be any 'causal flow' between
different attributes of the single substance that he identified both
with God and with Nature. This might make it appear that he have
endorsed statement (3) of our original trilemma at the price of
rejecting statement (1).
But when we read the Ethics from the other side of the 'linguistic
turn' in twentieth century Western philosophy, there is a strong
temptation to reinterpret Spinoza's metaphysical distinction between a
single substance and its many attributes. Post linguistic turn, this
amounts to the distinction between a single class of entities and the
plurality of equally well-grounded ways that may exist of describing
them. It is thus perhaps not too coercive to interpret Spinoza's
parallelism as implying that there is a systematic problem with the
practice of referring to mental and physical phenomena as entering
into causal relations with one another. But this is perfectly
consistent with the truth of statement (1). In this qualified sense,
then, Spinozistic parallelism may be viewed as a genuine historical
precursor to AM.
Two questions immediately arise about the doctrine of parallelism as
just described. First, if there really is an absolutely reliable
pairing-off between the constituents of physical and mental causal
chains, then why couldn't we just use characterizations of items in
Sequence B as though they referred to items in Sequence A? Why
couldn't claims about the "ideas" of objects be used in the natural
sciences, but there understood as merely abbreviating claims about
those physical objects themselves? The feature of Spinoza's philosophy
that makes it impossible for him to allow for this is his commitment
to causal rationalism – the thesis that for any genuinely causal
relationship one should always be able to deduce the effect from a
true description of the cause [see de Spinoza, 1949, p. 42ff]. This is
not a doctrine that would appeal to the sensibilities of many
contemporary philosophers, but it does turn out to have an important
analog in Davidson's treatment of the mind/body problem.
The second question that arises about Spinoza's parallelism concerns
the fact that even the very simplest and most transparent of mental
phenomena appear to depend for their existence upon a highly complex
collection of physical phenomena. But then why suppose that just any
physical event, no matter how simple (the movement of a single
electron, say) must have an ideational correlate? If one chooses to
hypothesize that a specific degree of physical complexity is necessary
for a mental phenomenon to occur, then the threat (or promise) of
reductionism looms. But most contemporary philosophers would certainly
favor reductionism over the alternative of panpsychism that Spinoza
himself embraces [de Spinoza, 1949, p. 90]. Interestingly Davidson
himself also ends up embracing an analog of panpsychism in the course
of his struggle to harmonize statements (1) –(3).
b. Verstehen Theory
Davidson's own views about the nature of mind emerged out of a set of
disputes that were instructively similar to the arguments that took
place among philosophers during the Cartesian era. For most of the
twentieth century, philosophers both on the European continent and in
English-speaking universities had been preoccupied with the autonomy
of humanistic enquiry. This issue was (and continues to be) a source
of disagreements that extend well beyond the relatively narrow
boundaries of metaphysical debate and into the realms of institutional
policymaking and literary and artistic culture. Among analytic
philosophers of the 1960s, disputes upon this general topic were
focused largely around a question that was partly epistemological and
partly ontological in its significance, whether or not it is
appropriate to view thereasons that people have for performing
specific actions as also themselves being causes of those actions.
According to one school of thought, which more or less began with the
Verstehen theorists of the nineteenth century – Wilhelm Dilthey, Max
Weber and Bendetto Croce, among others – the aim of the social
sciences and of humanistic enquiry in general is not the discovery of
causal relationships at all. To others, however – mechanists,
materialists and methodological monists about the sciences – such
claims were deemed to be either patently false or well-nigh
incomprehensible [See Anthony, 1989, p. 155, for a full discussion].
Seen against this backdrop, Davidson's own approach to the issue of
how reasons relate to causes takes on the appearance of a compromise
position. For Davidson both rejects reductionism and denies the view
that the distinction between reasons and causes is as absolute as the
Verstehentheorists wanted to claim.
In a famous example, Davidson describes a situation in which a
mountain climber accidentally causes the death of another man by
loosening his grip on a tethering rope. Suppose that this happened,
not because the first climber was deliberately setting out to do in
his comrade, but rather because he was merely "unnerved" by the
thought that he could make himself safer by ridding himself of the
extra weight. What we need, Davidson suggests, is to be able to
distinguish this sort of circumstance from a situation in which the
climber really does drop his comrade intentionally to rid himself of
the extra weight. In this second case, the reason (that the first
climber had for being concerned for his own safety) was also a cause
(of the death of the second climber). But then there is a
differentiation between reasons that are not causes and reasons which
are. [Davidson, 1973, p. 79]
In "Thinking Causes," Davidson explains the metaphysical significance
of these observations. He says here that "anomalous monism holds that
mental entities (particular time- and space-bound objects and events)
are physical entities, but that mental concepts are not reducible by
definition or natural law to physical concepts." [Davidson, 1993, p.
3]. Thus, while the sorts of mental events that we habitually identify
as reasons (under which broad classification he includes "perceivings,
notings, calculations, judgements, decisions, internal actions and
changes of belief" [Davidson, 1970, p. 208]) may also beidentified as
causes, this does not preclude us from being able to appeal to the
difference between reasons and causes as part of a general
characterization of what is distinctive about the human sciences.
The description of AM given thus far does nothing to distinguish it
from other, substantively different forms of so-called "property
dualism" in the contemporary philosophy of mind. We must first ask why
Davidson believes that mental events are identical with physical
events, and then ask why he nonetheless denies the reducibility of the
one to the other.
3. Mental Events are Physical Events
A crucial part of Davidson's overall strategy for reconciling
statements (1)-(3) is his endorsement of the thesis of token
physicalism (TKP). This is the doctrine that while mental properties
(types) cannot be identified with physical properties, mental
particulars (tokens) can be identified with particular,
spatio-temporally determinate physical entities. Davidson is not the
only influential analytic philosopher to have defended this doctrine,
but his reasons for doing so arise from a fairly idiosyncratic set of
views.
The most distinctive feature of Davidson's version of TKP is that it
is a doctrine about events, rather than processes, states, or (at
least in the primary instance) objects [see Davidson, 1970, p. 210].
His belief in the ontological primacy of events arises from the
underlying logical form of certain types of English sentences; the
fact that we can comprehend that sentences like "Jones buttered the
toast deliberately in the bathroom with a knife at midnight" entails
the sentence "Jones buttered the toast" cannot be explained (Davidson
thinks) without supposing that both make implicit reference to some
spatio-temporally bounded particular event [for the full argument, see
Davidson, 1967, pp. 105-107]. The identity conditions of events can
furthermore, he thinks, be established purely extensionally: event A
and event B are identical if and only if they have all of the same
causes and all of the same effects. [Davidson, 1969, p. 179]
When we successfully pick out an event by means of a mentalistic
description as being the cause of some other, physical event, we have
according to Davidson done all that is necessary to show that there is
mental causation. He traces this minimalist approach to the
classification of events as mental back to the writings of Elizabeth
Anscombe, who famously defended the view that all that is necessary
for an act's having been intended is that it be truly describable as
such [Davidson, 1967, p. 147]. So what, then counts as a genuinely
mentalistic description of any given event? Davidson's own views upon
this subject are less than entirely clear. In "Mental Events" he makes
the more general proposal that the hallmark of the mental is
intensionality. That is, true descriptions of mental events include a
verb with a subject that refers to a person, and a complement for
which the usual rules of substitution break down. Thus, while "Lois
thought that Clark Kent was lovely" would clearly count as a
mentalistic description of an event, since she might not have thought
the same about Superman, "Lois was smaller than Clark Kent" would fail
to satisfy the aforementioned criterion.
It is important to recognize, however, that intensionality is for
Davidson merely a sufficient condition for mentality; he does not seem
to regard it as being even close to necessary. This is clear from some
rather startling remarks that he makes in "Mental Events." He asks us
to consider "some event that we all intuitively accept as physical,
let's say the collision of two stars in distant space." If we can
truthfully describe this event as being merely simultaneous to some
other clearly mental event, then this fact is enough by itself,
Davidson thinks, for us to be warranted in describing the former
occurrence as a mental event too [Davidson, 1970, p. 211].
Davidson suggests that this sort of "Spinozistic extravagance" is
philosophically harmless to the case for AM because it provides us
with all the better reason for believing TKP. For the more inclusive
our criteria for mentality are, the more reason we will have to accept
that all mental events are identical to physical events [Davidson,
1970, p. 212]. But one thing that these considerations seem to imply
is that every event A that is caused by some mental event B will also
have the very same event as a physical cause. And this makes it look
as though the defender of AM will either have to explain away an
unpalatable form of causal over-determination in the natural sciences,
or else regard mental events as being purely epiphenomenal.
The claim that AM is really just epiphenomenalism in disguise has been
the single most common and widespread criticism of Davidson's thesis
since the publication of "Mental Events." The suggestion was first
made by Ted Honderich in a paper from 1982. Honderich draws a
suggestive analogy between mental properties and the properties
possessed by a bunch of green pears sitting on a grocer's scale. These
pieces of fruit maybe truly described as green, or as French, but the
fact that they possess these properties is clearly not what causes
them to make the scale read "1 lb." So why should the fact that we can
describe some events in ways that satisfy Davidson's rather permissive
criteria for mentality lead us to believe that the natural world
contains even a single instance of mental causation? [Honderich ,
1982, pp. 61-62]. The same objection is made somewhat more abstractly
by Jaegwon Kim when he described what he calls the "exclusion problem"
for mental causation. Suppose that an event m causes a distinct event
e, and that m has two properties, M and P. Furthermore suppose that
only the property P of m is connected by a strict causal law to some
property of e. But then, Kim asks how the property M can be understood
to be doing any "causal work" whatsoever [Kim, 1993, pp. 25-26].
Davidson responds to challenges of this general type by re-iterating
his commitment to a strictly extensionalist account of
event-causation. It is simply infelicitous, he thinks, to suppose that
whether or not one event is the cause of another depends upon our
ability to connect up their properties in any sort of statement
whatsoever, whether law-like or not. As he puts it in "Thinking
Causes,"
There is…no room for a concept of 'cause as' that would make
causality a relation among three or four entities rather than two. On
the view of events and causality assumed here, it makes no more sense
to say event c caused event e as instantiating law L than it makes to
say that a weighs less than b as belonging to sort c [Davidson, 1993,
p. 6].
Many philosophers have found this characterization of causality by
Davidson singularly implausible. For it does not seem as though
extensionalism by itself simply implies that events do not have the
causal powers that they do by virtue of falling under causal laws [see
McLaughlin, 1993, pp. 30-34]. And regardless of whether one is talking
about events, physical objects, thoughts, or whatever, it is surely a
perfectly natural and coherent question to ask whether it is because
something has a property M that it causes something else to have
property N. At least one recent defender of AM has suggested that
perhaps the very notion of causation itself is a fundamentally
ambiguous one, in the sense that its content changes depending upon
whether we employ the discrete standards of rational intelligibility
that are required by either a "personal" or an "impersonal"
perspective upon the natural world [see Hornsby, 1997, p. 140]. To
adopt this thesis about causation would appear to represent an
abandonment of the project of finding a genuinely intermediate
position between the approach favored by Verstehen theorists to
explanation in the human sciences and the traditional forms of
metaphysical materialism to which Davidson himself appears to be
willing to give at least qualified endorsement.
One of Davidson's earlier claims about the relationship between mind
and body is that the mentalsupervenes upon the physical. To say that
properties of type X supervene upon properties of type Y is at the
very least to commit oneself to the view that objects and events
cannot differ X-wise without also differing Y-wise. If this were in
fact the case, one could argue that there is at least some minimal
sense in which the possession of mental properties "makes a
difference" to the causal relations exhibited by particular physical
events. For, unlike the properties of color and nationality possessed
by the pears in Honderich's famous example, supervenient mental
properties are always going to stand in an empirically significant
relationship to the physical regularities that that are exhibited
among the physical properties that they supervene upon.
But the supervenience relation is one that has been characterized in
multitudinous different ways in late twentieth-century philosophy [See
Kim, 1990 for a fairly exhaustive catalogue]. Not all of the accounts
that have been given would provide equally good support for this
contention. According to Kim, the most pressing question about the
supervenience relation is whether it might actually entail the
reducibility of the supervenient class of properties or concepts to
their subvenient base. What, then, are some reasons that the defender
of AM might give for denying that mental concepts are simply reducible
to physical ones?
4. The Irreducibility of the Mental
a. Supervenience and Anomalous Monism
Davidson describes the relationship of supervenience as the key to
understanding how mental phenomena may be "in some sense dependent"
upon physical phenomena in spite of there not being any strict
psycho-physical laws [Davidson, 1970, p. 214]. He clearly regards the
notion of supervenience as representing a sort of panacea for anyone
skeptical about the possibility of reconciling statements (1)-(3)
[Davidson, 1993, p. 4]. So what, precisely, is the supervenience
relation supposed to amount to?
The earliest instance of an appeal to the notion of supervenience in
the twentieth century was by S.E. Pepper, in a paper first published
in 1926. Pepper used the word "supervenient" to refer to a type
ofchange that gives rise to emergent properties in the objects
undergoing the relevant transformation [see van Brakel, 1999, pp.
4-5]. Over the last thirty years of the twentieth century, the term
"supervenience" came to be used by philosophers in a wide variety of
contexts, not only in ethics and the philosophy of mind, but in areas
as diverse as aesthetics, modal metaphysics, the philosophy of biology
and philosophical theology. Davidson himself acknowledges having
borrowed the term from R.M. Hare's discussion of the relationship
between ethical and natural properties in The Language of Morals.
Unlike Pepper, both Hare and Davidson characterize supervenience in
explicitly linguistic terms, without reference to metaphysical notions
like emergence that is supposed to be antecedently clear. Thus, for
Davidson, "a predicate P is supervenient on a set of predicates S if
and only if P does not distinguish any entities that cannot be
distinguished by S" [Davidson, 1993, p. 4].
What is most striking about this characterization of the supervenience
relation is its apparent weakness. When we make a Davidsonian
supervenience claim we do not undertake any commitment whatsoever to
the thesis that the supervening predicate can be could be shown to be
redundant by even the most vigorous applications of Ockham's razor.
In "Mental Events" Davidson develops two puzzling but suggestive
analogies for the way in which the mental may be thought of as
supervening upon the physical. He first suggests that we think of
mentalistic predicates as being like the Tarskian truth predicate and
the vocabulary of physics as being like the resources that are present
within a natural language to describe its own syntax. For the truth
predicate as Tarski describes it had the following important
characteristic: it cannot be defined using only the resources of the
object language, even though one might well be able to pick out all of
the sentences that lie within its extension [see Davidson, 1970, pp.
214-215]. The other comparison that he makes involves an allusion to
the failure of what he refers to as "definitional behaviorism" in
scientific psychology. This theory was abandoned by empirical
psychologists, he suggests, not because of any single piece of
disconfirming evidence, but rather because they noticed "system in the
failures" of behaviorists to define concepts like belief and desire in
explicitly behavioral terms [see Davidson, 1970, p. 217].
In contrast to these suggestive but rather underdeveloped analogies,
Jaegwon Kim famously argues that the supervenience of a class of
properties G upon another class D actually entails that G is reducible
to D[see Kim, 1984, p. 78]. If this claim were correct, then it would
certainly be difficult to see how a Davidsonian could claim that there
were no strict laws of nature connecting mental properties with
physical ones. It is less clear that from Davidson's own
characterizations of supervenience in terms of the mere
distinguishability of objects represents a weaker notion than that
which is favored by reductionists following Kim.
A somewhat more subtle and less radical criticism of Davidson's use of
the supervenience relation to defend AM has been offered by Simon
Blackburn. Blackburn parses supervenience claims as non-trivial
restrictions upon how we conceive of the possibility that different
sorts of objects could exist within the same world. Even the weakest
sorts of supervenience claims, he suggests, involves implicit
reference to the notion that an object has some property as the result
of also possessing what he refers to an "underlying" set of natural
(i.e. physical) properties. To say that property M supervenes upon
property P, then, is to make an assertion with the following logical
form:
(S) Necessarily, if there exists some x such that Mx and Px and if
Px underlies Mx, then, for all y, if Py then My [Blackburn, 1985, p.
131].
Blackburn points out that the truth of any instance of (S) would be
perfectly consistent with there beingsome possible worlds containing
objects which have P (which may turn out to be some extremely complex
or disjunctive physical property) while lacking M. Nonetheless, he
thinks that our default modal intuitions should cause us to rankle
whenever we are presented with a claim having the form of (S). We
should react this way, he thinks, because (S) represents a violation
of what he calls the "principle of plentitude" about possible worlds.
Why shouldn't there be possible worlds in which some objects or events
that instantiate a given set of physical predicates also instantiate a
given mental property, while others do not? This, according to
Blackburn, is the key metaphysical question that the doctrine of AM
compels us to ask, but for which its advocates have never really
provided an answer [Blackburn, 1985, p. 135].
According to Blackburn's recipe for supervenience, "underlying"
properties will always be physical ones. It thus seems pretty clear
that violations of the "principle of plentitude" about possible worlds
of the sort that Blackburn is talking about here must occur at the
level of nomological (as opposed to logical, metaphysical or
epistemic) possibility. The advocate of AM would surely, after all,
not want to deny that it is at least logically possible for a world to
contain two physically identical beings, one with a mind and one
without, not that such a circumstance fell entirely outside the range
of human conceivability. Thus, if the question that Blackburn asks
about supervenience is the right one to pose to the anomalous monist,
then we may at this stage draw an important methodological conclusion.
It looks as though Davidson's claim that the mental supervenes upon
the physical is, after all, really just another way of stating his
commitment to the impossibility of strict natural laws connecting
mental and physical phenomena. In order to understand why the advocate
of AM will be committed to the irreducibility of the mental, then, one
need only ask what he thinks it is about instances of mental causation
that makes them insusceptible to the sort of explanation that can be
provided by appeal to so-called "strict" natural laws.
b. "Strict" and "Non-Strict" Natural Laws
A universal generalization is law-like, according to Davidson, just so
long as it provides support for a suitably broad set of subjunctive
and counterfactual conditionals. For example, the statement "Whenever
it rains, the grass gets wet" might well count as law-like, since it
provides at least partial supports for the claims "If it were to rain
next week, the grass would be wet" and "If it had not rained this
morning, the grass would not presently be wet" – provided, at least,
that we restrict our attention to possible words where a sprinkler is
not available. A law-like statement also qualifies as "homonomic" if
the scope of its generality can be increased by means of "adding
further provisos and conditions," all of which can be stated in "the
same general vocabulary as the original statement." "Whenever it
rains, the grass gets wet" would thus presumably fail to count as
homonomic, since the ceteris paribus clause "…unless someone has
pitched a tent in the yard" is not a statement that makes exclusive
use of the language of meteorology.
A strict law of nature for Davidson will thus be a homonomic law-like
generalization that has been supplemented to the fullest possible
extent by ceteris paribus clauses that do not violate this
restriction. All general causal statements connecting mentalistic and
physicalistic concepts must, according to Davidson, be regarded as
non-strict, or "heteronomic" in nature.
Davidson proposes, controversially, that the criterion just described
for what it takes to be a natural law is an a priori truth [see
Davidson, 1970, pp. 216-220]. But from whence comes his confidence
that it is possible, even in principle, to come up with these sorts of
generalization anywhere in the natural sciences? He repeatedly claims
that such completely exceptionless generalizations are most likely to
be found in theoretical physics. But this assertion is not defended.
Furthermore, even if he is right that such perfectly "strict" laws of
nature could in principle be set down, the question remains whether
there are good reasons to suspect that any of the vocabulary currently
available for use in the natural sciences is suitable for the
formulation of these sorts of statements. In response to these sorts
of concerns, a fairly broad contingent of philosophers of science have
defended accounts of the concept of a natural law which represent
scientific knowledge as being heteronomic through and through [See
e.g. Cartwright, 1994 and Fodor 1974].
Another more subtle issue has been raised by some philosophers in
connection with Davidson's rather thin conception of natural law. It
seems possible to identify a fairly broad class of generalizations
whose status as laws of nature does not depend upon either their
predictive usefulness or the vocabulary within which ceteris paribus
clauses for them are formulated. These are what Robert Cummins calls
"instantiation laws." The logical form of instantiation laws, as
Cummins describes them, is as follows: Anything having components
C1…Cn organized in manner O has property P [See Cummins, 1981, p. 17].
Such generalizations serve to explain what it is about the structure
of some system that makes the system an instantiation of a given
property. They do not explain how it is that that system's properties
change over time. Entries in the Periodic Table of the elements would
appear to qualify as expressions of this sort of law, since the
information that they communicate is that the arrangement of a
specific number of electrons around an atomic nucleus at a given set
of energy levels is what makes one atom count as a sample of hydrogen,
oxygen, iron, etc.
Even if there were no psycho-physical laws in Davidson's sense of the
term, mightn't there in fact be plenty of psycho-physical
instantiation laws? Perhaps the only way to explain changes in belief
or short-term memory is by making generalizations that refer (either
implicitly or explicitly) to other beliefs or memories. But it seems
perfectly cogent to suppose that, even if this were true, we might be
able to explain what it is that makes some particular state of a
person (or her neurosystem) a belief or a memory in a purely
neurophysiological vocabulary. How would it affect the case for AM if
it were to turn out that we could make these sorts of generalizations
connecting physical concepts with mentalistic ones?
Upon this topic, opinions diverge quite broadly. Louise Anthony has
suggested that, once we recognize the possibility of formulating
psycho-physical "instantiation laws," we will be able to reject
statement (3) in a way sensitive to the intuition underlying
Davidson's mountain climber thought experiment. This would, of course,
be bad news for the advocate of AM. But Nick Zangwill has suggested
that something like the spirit of AM could be preserved even if one
were to accept the possibility of what he calls "strict derivative
causal laws" (SDLs). Laws of this character, which are quite common in
the sciences (according to Zangwill) combine the causal information
that instantiations of a property M are followed by instantiations of
a property M* with the "metaphysical" information that a system that
instantiates M* will do so because it is of type P. It seems easy
enough, indeed, to think up putative instances of this type of natural
law – consider, for example, the claim that an occurrent general
desire for nourishment (M) in a creature whose senses can detect hot
oatmeal nearby (P) will normally (ceteris paribus, of course) bring
about a more specific desire for oatmeal (M*).
If there are true SDLs that connect up the vocabulary of psychology
with the vocabulary of physical science in this sort of way, then
there is at least one sense in which statement (3) must clearly be
regarded as false. But Zangwill proposes that the defender of AM may
still have good grounds for believing that mental phenomena are
anomalous in something very much like the way that Davidson originally
supposed. For SDLs will generally lack the sort of explanatory
significance that "strict" laws of nature, in the Davidsonian sense of
the term, may generally be thought to have. They are clearly not the
sorts of generalizations that could be conclusively verified without
appeal to a background theory consisting at least for the most part of
more simply structured law-like generalizations. Furthermore, the
underlying physical properties referred to within putatively
psycho-physical SDLs are likely to be so wildly disjunctive in nature
that such "laws" might normally end up covering nothing more than a
single actual instance of mental causation [see Zangwill, 1993, pp.
69-76].
There do, then, appear to be a wide variety of claims that differ both
in content and in logical form, but which may nonetheless be entirely
plausible candidates for the status of laws of nature. But then from
whence comes the surprisingly powerful conviction shared by Davidson
and his sympathizers of the falsity of statement (3)? It is impossible
to understand why Davidson subscribes to this radical view without
becoming acquainted with his views about the norms of empirical
methodology that govern all forms of humanistic enquiry. An
examination of what he says upon this general subject will therefore
help to shed light upon what motivates him to claim that the concepts
referred to by mental and physical predicates are simply not 'made
for' one another.
5. A Methodological Postscript
The extent to which Davidson's commitment to AM turns out to derive
from his views about methodology is partly obscured by his own
tendency (shared by the majority of both his followers and his
critics) to discuss issues connected with the mind/body problem in
traditionally metaphysical terms. But whenever he actually sets about
the task of defending statement (1), what is at issue always turns out
to be a distinctively methodological question. When we set about
explaining the actions of other human beings, to what extent must we
employ our own, perhaps entirely parochial, standards for determining
what counts as rational behavior?
In his discussion of the two mountain climbers, for example, the
identification of the second climber's decision to let his companion
fall as mental causation serves the purpose of providing us with a
means for ascribing responsibility. And one could think up other
scenarios with relative ease within which the same sort of appeal to
the causal efficacy of the mental could be used to bolster our
intuitions about an agent'smoral praiseworthiness, his independence
from physical coercion or his very sanity. It is this cluster of
distinctly normative concepts that seem to represent the principal
ingredients in our everyday concept of rationality.
Once one understands this feature of Davidson's philosophical program,
it becomes considerably clearer what is really going on in the two
analogies from "Mental Events," that is, his comparison of the
mental/physical distinction in metaphysics to the difference between
semantics and syntax and to the failure of behaviorism to supplant
belief/desire psychology. Because the methodology whereby radically
unfamiliar languages may be interpreted requires us to treat the
speakers of these languages as predominantly rational, for Davidson
semantics cannot be reduced to syntax [Davidson, 1973b, pp. 134-137].
And it is because the attribution of rationally ordered beliefs and
desires is a constitutive feature of all psychological explanation
that this pair of concepts are not susceptible to the sorts of
reductive accounts sought by the "definitional behaviorist."
Davidson's belief in the impossibility of fitting together mental and
physicalistic concepts into statements that express strict laws of
nature is just one more instance of this general pattern of insisting
upon a rigorous distinction between descriptive and normative
considerations in scientific methodology.
New problems will of course arise for the defender of AM who treats it
as a straightforward consequence of these sorts of methodological
considerations. It might, for example, be protested that
considerations to do with the a priori, constitutive constraints that
govern the interpretation of human speech, thought, and action have no
obvious implications at all when it comes to assessing the
plausibility of statement (3). Philosophers have, after all, had
widely divergent intuitions about just what the connection might be
between such normative injunctions and the laws of nature. Kim, for
example, suggests that if the relevant constraints upon human ethology
are as different from those that operate in the rest of the sciences
as Davidson thinks they are, then there should surely be no true
law-like generalizations – strict or non-strict – connecting mental
properties with physical ones [Kim, 1993, p. 25]. Whereas Blackburn
remarks that there seems to be no intrinsic reason to suppose that
"interesting laws" could be discovered even between properties the
attribution of which "answers to different constraints." [Blackburn,
1985, p. 140]
Other more general worries arise in connection with the very idea that
the concept of causation has a distinctive sort of usefulness in
explicitly normative contexts. This belief of Davidson's makes it look
as though he might, after all, be implicitly committed to a type of
causal rationalism. For suppose our claim that the malicious climber's
deliberate decision to cut his comrade loose caused the latter's death
is partially underwritten by the sorts of normative considerations
that Davidson identifies. Our very decision to describe the climber as
having deliberated at all, then, will have been partly motivated by
our felt need to hold him responsible for the death of his comrade.
But in this case, our descriptions of the cause and of the effect
would appear to lack the sort of logical independence from one another
that true causal statements are usually (or at least
common-sensically) required to have. This observation does not by
itself represent a straightforward refutation of Davidson's position –
after all, as we have seen, causal rationalism was openly embraced by
Spinoza, as well as by many other philosophers of the early
Enlightenment. But it does make Davidson's views about causation start
to look very strange to contemporary sensibilities.
It appears as though coming to a final verdict upon the plausibility
of AM would require one to engage in some much more general
reflections about the relationship between how we go about obtaining
our beliefs about the world – specifically the parts of it that are
relevant to the aspiring interpreter of human thought and language –
and what sorts of beings that world objectively contains. That we find
ourselves faced with this daunting prospect when we try to determine
the prospects for achieving a reconciliation of statements (1)-(3) is
perhaps something of a disappointment. But it should also perhaps not
surprise one too much. The general problem of discerning where the
boundary lies between epistemology and metaphysics is, after all, just
one more part of the Cartesian legacy.
6. References and Further Reading
* Anthony, Louise, "Anomalous Monism and the Problem of
Explanatory Force," The Philosophical Review vol. 48 (1989), 153-187.
* Anthony, Louise, "The Inadequacy of Anomalous Monism as A
Realist Theory of Mind," in G. Preyer et. al (eds.) Language, Mind and
Epistemology: On Donald Davidson's Philosophy (Dordrecht: Kluwer
Academic Publishers, 1994), 223-253.
* Bennett, Jonathan, A Study of Spinoza's Ethics (Indianapolis:
Hackett, 1984).
* Blackburn, Simon, "Supervenience Revisited," reprinted in Essays
in Quasi-Realism (New York: Oxford University Press, 1993), 130-148.
First published in 1985.
* Cartwright, Nancy, "Fundamentalism versus the Patchwork of
Laws," Proceedings from the Aristotelian Society 94 (1994), 279-292.
* Cummins, Robert, The Nature of Psychological Explanation
(Cambridge, Mass.: The MIT Press, 1981).
* Davidson, Donald, "The Logical Form of Action Sentences,"
reprinted in Essays on Actions and Events(Oxford: Clarendon Press,
1980), 105-149. First published in 1967.
* Davidson, Donald, "The Individuation of Events," reprinted in
Essays on Actions and Events (Oxford: Clarendon Press, 1980), 163-180.
First published in 1969.
* Davidson, Donald, "Mental Events," reprinted in Essays on
Actions and Events (Oxford: Clarendon Press, 1980), 207-224. First
published in 1970.
* Davidson, Donald, "Freedom to Act," reprinted in Essays on
Actions and Events (Oxford: Clarendon Press, 1980), 63-82. First
published in 1973.
* Davidson, Donald, "Radical Interpretation," reprinted in
Inquiries into Truth and Interpretation(Oxford: Clarendon Press,
1984), 125-150. First published in 1973 (b).
* Davidson, Donald, "Psychology as Philosophy," reprinted in
Essays on Actions and Events (Oxford: Clarendon Press, 1980), 229-239.
First published in 1974.
* Davidson, Donald, "Thinking Causes," in John Heil and Alfred
Mele (eds.) Mental Causation (Oxford, Clarendon Press, 1993), 3-18.
* Fodor, Jerry, "Special Sciences (or, the Disunity of Science as
a Working Hypothesis)," Synthese 28 (1974), 97-115.
* Honderich, Ted, "The Argument for Anomalous Monism," Analysis 16
(1982), 59-64.
* Hornsby, Jennifer, Simple Mindedness (Cambridge, Mass: Harvard
University Press, 1997).
* Kim, Jaegwon, "Concepts of Supervenience" reprinted in
Supervenience and Mind (New York: Cambridge University Press, 1993),
53-78. First published in 1984.
* Kim, Jaegwon, "Supervenience as a Philosophical Concept,"
Metaphilosophy 20 (1990), 1-27.
* Kim, Jaegwon, "Can Supervenience Save Anomalous Monism?" in John
Heil and Alfred Mele (eds.)Mental Causation (Oxford, Clarendon Press,
1993), 19-27.
* McLaughlin, Brian, "On Davidson's Response to the Charge of
Epiphenomenalism in John Heil and Alfred Mele (eds.) Mental Causation
(Oxford, Clarendon Press, 1993), 27-41.
* Spinoza, Benedict de, Ethics, James Gutmann, ed. (New York: Hafner, 1949).
* Van Brakel, J., "Supervenience and Anomalous Monism," Dialectica
53 (1999), 3-24.
* Zangwill, Nick, "Supervenience and Anomalous Monism: Blackburn
On Davidson," Philosophical Studies 71 (1993), 59-79.
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