On ‘emergence’
in philosophy
In philosophy, ‘emergence’ is a semi-technical
term whose meaning calls for stipulation as much as description since, unlike every
day words with lives outside philosophy though subject to philosophical investigation,
for example ‘knowledge’, it lacks a settled use. I take it, however, to be
related, but to stand in contrast, to reduction.
Consider the length of a standard 4 x
2 stud Lego brick (that is 4 studs in length and 2 wide). These are 31.8 mm and
they are constructed so that when slotted onto a studded base they leave a 0.2mm
gap between bricks (to stop them sticking). Thus the effective length of a brick
is 32mm. And thus a Lego building built using a line of 10 such bricks will have
a length of 32mm x 10 – 2 x 0.1mm = 319.8mm or approximately 320mm. That overall
length results from the combination of the basic length of the bricks, the ‘logic’
of the combination (in this case the small engineered gap between each) and some
basic mathematics. The overall length can thus be reduced to a combination of the
basic properties of the components. But the overall length would not, within philosophy,
generally be said to emerge from those
basic properties.
The mind, by contrast, is often said to
be an emergent property. Tom Nagel proposes a distinction between reductive and
emergent in the following way:
A reductive account will explain
the mental character of complex organisms entirely in terms of the properties
of their elementary constituents… An emergent account, by contrast, will explain the mental
character of complex organisms by principles specifically linking mental states and processes to the complex physical functioning of
those organisms—to their central nervous systems in particular, in the case of
humans and creatures somewhat like them. The
difference from a reductive account is that, while the principles do not reduce
the mental to the physical, the connections they specify between the mental and
the physical are all higher-order. [Nagel 2012: 54-5]
(Nagel uses the term
‘reductive’ for analyses or explanations of complex wholes using whatever
properties of their most basic elements and ‘reductionist’ for a subset of
those using exclusively physical properties.)
This use of ‘emerge’ attempts to reconcile
two opposing intuitions. On the one hand, the mind is something to do with the brain or brain and body or
brain, body and world. Perhaps it is a causal effect or perhaps a redescription
highlighting different properties. Certainly possession of a brain seems to play
a central role in also having a mind. And yet, on the other hand, it seems mysterious
how the combination of the merely physical properties of physical material can
result in the mind, or mental properties.
Two particular features of the mind seem
to drive this latter intuition. First, the qualitative aspects, the phenomenology
(small ‘p’) or qualia, of experiential states seem quite unrelated to physical properties.
But second, the ‘aboutness’ or intentionality (another semi-technical term for the
world-directedness of content-laden mental states or propositional attitudes) of
mental states, the ability to have thoughts about things whether real or unreal,
appears unlike any basic physical property. And hence some philosophers (and others
outside philosophy) say that the mind is an ‘emergent’ property of the brain, or
brain and body, or brain, body and world
Not all philosophers share this view of
the intractability of the second intuition. In a book on intentionality, Jerry Fodor
offers the following rationale for reductionism about the mind:
I suppose that sooner or later the
physicists will complete the catalogue they’ve been compiling of the ultimate and
irreducible properties of things. When they do, the likes of spin, charm
and charge will perhaps appear upon their list. But aboutness surely
won’t; intentionality simply doesn’t go that deep. It’s hard to see, in face of
this consideration, how one can be a Realist about intentionality without also being,
to some extent or other, a Reductionist. If the semantic and intentional are real
properties of things, it must be in virtue of their identity with (or maybe of their
supervenience on?) properties that are neither intentional nor semantic.
If aboutness is real, it must be really something else. [Fodor 1987: 97]
The
argument turns on the idea that a future completed physics serves as the benchmark
of what is real. For any property there then seem to be only three possibilities.
·
They appear on the basic list.
·
They are reducible to something on the basic list.
·
Or they are not a real property after all.
Since the aboutness or intentionality of mental states is
both real and ‘doesn’t go [as] deep’ as fundamental physics, it seems that it must
be reducible to something on that list.
In fact
the passage hedges its bets by introducing, in parenthesis, the possibility of something
weaker. Perhaps intentional properties are real in virtue of merely their supervenience on fundamental physics. Supervenience
is a brute dependency: fixing the physical fixes the mental but not vice versa.
Thus this remark looks to acknowledge the possibility of the intractability of the
second intuition above: that mental properties cannot be reduced. In fact, however,
Fodor does aim to reduce intentional
properties by combining an explanation of the systematicity and
compositionality of thought via structured mental representations or symbols in
a language of thought with a variant of a causal theory of how the symbols come
to have worldly content or reference [Fodor 1987, 2008].
Nevertheless,
Fodor’s argument highlights a key question, and hence distinction, in thinking about
the motivation for emergence understood in this broad way. What is the nature of
the mystery of the dependence of, in this case, mind on brain, body and external
world? It could be that it marks a contingent de facto epistemic lack. Perhaps,
for example, we cannot explain the connection at present. If so, some further work
would be needed to articulate the standard of explanation in play. If, for example,
it is the provision of some causal information a la David Lewis then some explanation
of the connection of mind and body does seem to be available (minimally: the occurrence
of the Big Bang) [Lewis 1986]. If, on the other hand, it requires a logically sufficient
condition, then almost nothing in the universe can be explained [Hempel 1965].
A more
promising approach is to look for a reason for the lack of explanation. We may lack
an explanation of the general relation between mind and body because no such general
explanation is possible because the kind of relation on which it would rely does
not, and perhaps could not, exist. That would provide a principled distinction between
reduction and emergence. In what follows in this brief note I will take this as
a clue to emergence.
Davidson and radical interpretation
Fodor
aims to shed on the nature of intentionality by reducing it. On his account mental
content is supposed to reduce to, rather emerge from, neural states. But my focus
here is with a contrasting approach to intentionality: the anti-reductionist approach
of the recent American philosopher Donald Davidson. Davidson examines the nature
of both linguistic meaning and mental content through the thought experiment of
radical interpretation. His aim is to clarify the nature of both linguistic meaning
and mental content more generally by examining how it is determined in radical interpretation.
‘What a fully informed interpreter could learn about what a speaker means is all
there is to learn; the same goes for what the speaker believes’ [Davidson 1983:
315].
Radical
interpretation is interpretation from scratch [Davidson 1993: 77]. It is a philosophical
abstraction from the kind of interpretation undertaken by a field linguist having
first contact with an alien tribe. Such interpretation cannot appeal to bilingual
speakers or dictionaries because it precedes those resources. Furthermore, it cannot
presuppose access to the content of the mental states of speakers. Whatever the
connection between mental content and linguistic meaning, radical interpretation
must earn access to, and cannot simply assume, facts about both. The intentional
contents to which Grice appeals in the analysis of linguistic interchange, for example,
cannot be identified prior to the interpretation of the agent’s language [Grice
1957]. Thus they cannot be appealed to in radical interpretation. Interpretation
must, instead, rely only on the evidence of correlations between utterances and
the circumstances which prompt them:
[The radical interpreter] interprets
sentences held true (which is not to be distinguished from attributing beliefs)
according to the events and objects in the outside world that cause the sentence
to be held true. [Davidson 1983: 317]
Davidson
thinks that the facts about mental content have to be determined in the same way.
Meanings and contents are interdependent. This presents a principled difficulty
for radical interpretation:
A speaker who holds a sentence to
be true on an occasion does so in part because of what he means, or would mean,
by an utterance of that sentence, and in part because of what he believes. If all
we have to go on is the fact of honest utterance, we cannot infer the belief without
knowing the meaning, and have no chance of inferring the meaning without the belief.
[Davidson 1984: 142]
Thus
the interpreter faces the task of unravelling two sets of unknowns - facts about
meaning and facts about beliefs - with only one sort of evidence: linguistic actions
which depend on both meaning and belief. Normally, we can find out what someone
believes by asking them. But that presupposes we know what they mean. Equally, if
we know what they believe then we can use this to establish what they mean in expressions
of their beliefs. But if both factors are simultaneously unknown, how can one break
into the circle?
Davidson’s
solution has two ingredients. Firstly, he takes the evidential basis of radical
interpretation to be the prompted assent of a speaker, which he characterises as
‘the causal relation between assenting to a sentence and the cause of such assent.’
[Davidson 1983: 315] It is possible to know that a speaker assents to a sentence
without knowing what the sentence means and thus what belief is expressed by it
(or vice versa). Characterising a speaker as holding a particular sentence true
is an intentional interpretation of what is going on - the speaker is described
by relation to a propositional content - but it does not presuppose a semantic
analysis of the sentence. That will be derived later.
The
second step is to restrain the degrees of freedom of possible beliefs in order to
interpret linguistic meaning. The interpreter must impose his or her own standards
of truth and coherence on ascriptions of beliefs and meanings. There must be a presumption
that any utterance or belief held true is true and that beliefs are structured
in accordance with basic logic, probability theory and decision theory. This
underpins the interpretation of familiar logical connectives such as ‘and’,
‘or’, ‘not’ etc. [Davidson 1990: 326-328].
This
complex of related assumptions governing the rationality imputed - generally briskly
labelled the ‘Principle of Charity’ - enables interpretation to get off the ground.
If utterances and underlying beliefs are assumed by the interpreter to be generally
true, rationally structured and to concern the worldly states of affairs which prompt
them, then they can be correlated with those observed states of affairs and their
meaning determined.
But
Davidson goes further. He argues that the facts available to radical interpretation
are the only facts about meaning there are. After all, the only justification that can be offered for knowledge
of a first language – the only potentially
contrasting case – depends on facts available from the radical interpretation of
the contextually located utterances of kith and kin. Since access to the only facts
there are about meaning has to be mediated by the Principle of Charity, this is
not merely an epistemological shortcut.
It reflects an ontological feature of
belief content and linguistic meaning itself. Both are governed by a constitutive
principle: the ‘Constitutive Ideal of Rationality’ [Davidson 1980: 223]. Belief
and meaning (both facets of human intentionality) are essentially governed by rationality.
Reduction to, or emergence from, the physical?
Davidson’s
account of radical interpretation is a development from his teacher
W.V.O. Quine’s account of a similar thought experiment: radical translation
[Quine 1960: 26-79]. But one key difference is its characterisation of the evidence
available to the interpreter or translator:
The crucial point on which I am with
Quine might be put: all the evidence for or against a theory of truth (interpretation,
translation) comes in the form of facts about what events or situations in the world
cause, or would cause, speakers to assent to, or dissent from, each sentence in
the speaker’s repertoire. We probably differ on some details. Quine describes the
events or situations in terms of patterns of stimulation, while I prefer a description
in terms more like those of the sentence being studied; Quine would give more weight
to a grading of sentences in terms of observationality than I would; and where he
likes assent and dissent because they suggest a behaviouristic test, I despair of
behaviourism and accept frankly intensional attitudes toward sentences, such as
holding true. [Davidson 1984: 230]
Davidson
realises that his project cannot escape all meaning-related notions and especially
in later accounts drops the requirements about its non-semantic nature:
My way of trying to give an account
of language and meaning makes essential use of such concepts as those of beliefs
and intention, and I do not believe it is possible to reduce these notions to anything
more scientific or behaviouristic. What I have tried to do is give an account of
meaning (interpretation) that makes no essential use of unexplained linguistic
concepts. (Even this is a little stronger than what I think is possible.) It will
ruin no plan of mine if in saying what an interpreter knows it is necessary to use
a so-called intensional notion - one that consorts with belief and intention and
the like. [Davidson 1984: 175-6]
This
is significant because it marks a distinction between Quine’s scientistic project
of reducing meaning-related notions to
behaviouristic notions and hence, in principle at least, initiating a first reductionist
step. Davidson has no such aims.
Further,
a key aspect of Davidson’s broader philosophy of mind is to argue that the Constitutive
Ideal of Rationality has ‘no echo in physical theory’ [Davidson 1980: 231]. Hence
there cannot be lawlike relations between the rational domain of mental states and
the nomological domain of underpinning neurological or physical states. Such lawlike
connections would violate the constitutive principles of the mental. So mental content
cannot be reduced to neural properties. The most there can be is something like
emergence of the mental from the physical
domain.
Reduction to, or emergence from, the rational?
Although
Davidson denies the possibility of a reductionist project, using that word in Nagel’s
sense to mean reducing mental properties to physical properties, the argument from
radical interpretation nevertheless suggests a reductive project. Facts about
meaning and mental content are reduced to a prior understanding of the demands
of rationality in accord with the Principle of Charity. But the connection
between meaning and mental content, on the one hand, and rationality, on the
other, might place explanatory priority differently akin to the Euthyphro
dilemma. Given a suitable theology, the following biconditional would be true:
·
For any act x: x is pious if and only if x is loved by the gods.
The
dilemma stems from considering the ‘order of determination’, in Crispin
Wright’s phrase, of this biconditional [Wright 1992]. Is the pious loved by the
gods because it is pious, or is it pious because it is loved by the gods? In
the epistemic approach to it outlined above, it looks as though Radical
Interpretation explains meaning and mental content in terms of rationality. But
it may be the case that the connection highlights an ontological dependence the
other way. Or, it may be that there is equal priority.
One
reason for denying that it is the first priority is the idea that grasping the
meaning of words introduces new rational norms or ‘oughts’. Davidson himself
argues that the output of Radical Interpretation can be codified using the
logical machinery of Tarski’s semantic conception of truth [Tarski 1944].
Tarski uses this to shed light on the nature of truth (or, more accurately, the
set of truths expressible in a language) presupposing facts about meaning.
Davidson inverts that use to shed light on meaning by presupposing truth, in
accord with the Principle of Charity. A central feature of both Tarskian and Davidsonian
approaches is the derivation of instances of what is called the ‘T-schema’:
·
‘Snow is white’ is true if and only if snow is white.
It
has been argued that meaning relations as exemplified in instances of the
T-schema are merely descriptive rather than normative [Hattiangadi 2006]. One argument
for that is that it is hard to see how the norm in question could be, for
example, a moral ought since there is no general moral obligation to use ‘snow’
to speak of snow. So what kind of ‘ought’ could it be?
But
in accord with the general though experiment of radical interpretation – that
is, if the ground rules for that thought experiment are accepted – such an
equivalence is surely not normatively inert:
[W]hat makes it correct among
speakers of English to make a claim with, say, the words ‘Snow is white’... is that
snow is indeed white. I stress ‘correct’: truth in the sense of disquotability...
is unproblematically normative for the practice of using the sentence mentioned
on the left-hand side of T-sentences. [McDowell 2009: 214]
The
equivalence expresses the kind of normative standard on which Radical
Interpretation is built. In order to break into the circle of interdependence
of belief and meaning, the Principle of Charity imposes rational constraints
that speakers believe and say what they ought to in this sense. In this case,
in order to say that snow is white in English, one ought to say ‘Snow is
white’. Such a principle is part of the armoury of the radical interpreter in
his or her broader holistic project of interpretation. The normativity,
however, is not moral or prudential or any other species but specifically
semantic.
On the Tarskian-Davidsonian conception
the ‘oughts’ in question – the ‘oughts’ that are built into the idea of, say, denotation
– are not separable from the idea of correctness in assertion... I think once we
see that the intuition that meaning and aboutness are ‘ought’-laden does not require
the relevant ‘oughts’ to be pre-semantical... we can see that there is no ground
for the idea that linguistic behaviour must be governed by... proprieties that can
be formulated in non-semantical terms... [McDowell 2009: 215-6]
The
distinction between semantic and other kinds of normativity does not undermine
the normativity of the former. It is sui generis. But its location within the
broader framework of radical Interpretation suggests that it is nevertheless
bound by the Constitutive Ideal of Rationality.
Davidson’s
own presentation of Radical Interpretation seems to suggest that meaning is accessible
to any rational subject since the standards of rationality mentioned are as
general as logic, probability theory, and decision theory. Indeed, this thought
underpins his argument against the very idea of many untranslatable and also of
a single substantial conceptual schemes or scheme [Davidson 1984: 183-98].
Changing
the priority suggests another possibility. If rationality and meaning go hand
in hand, the rationality relevant for a particular tract of meaning may require
a particular kind of mind. It may take a particular special design of mind to respond
to and grasp certain kinds of meaning. Rationality may not be a universal ‘cognitive
prosthetic’ in Charles Travis’ phrase. He says:
Our special design opens our eyes,
as [John McDowell] puts it, to particular tracts of reality. That our eyes may be
thus opened shows where, and how, there may be facts that it takes special capacities,
not enjoyed by just any thinker, to see... Special knowledge-yielding capacities
may be insusceptible to cognitive prosthetics. That is, what, with them, one is
equipped to see need not be what would be derivable from some statable set of principles
by a thinker lacking those capacities. [Travis 2002: 305, 325].
McDowell’s
invocation of special design is usually associated with sensitivity to moral
demands. The idea is this. On the assumption that, notwithstanding the
influential contrary tradition in the moral philosophy, moral judgement cannot
be codified in a set of principles, it must instead answer to the values
inhering in worldly situations: moral particulars (or the evaluative equivalent
of the facts to which empirical judgements answer). But in order to address a
potential disanalogy with at least some empirical facts concerning primary
qualities such as length and mass, McDowell suggests that moral values may be
akin to secondary qualities such as colour, taste and smell. Grasp of secondary
qualities and moral properties requires having a particular kind of perceptual
system, or mind, or underpinning way of life: our special design. This in turn
suggests that to understand those concepts, the meaning of the relevant words,
and the norms that govern them also requires having a special design.
The
possibility of an equal priority in the relation between the ideal of
rationality and the facts about meaning and mental content it structures and
the additional plausibility of the idea that some concepts are not accessible
to just any rational subject suggests a more complex picture of the emergence
of mind or, rather, minds. Whilst Davidson’s presentation of radical
interpretation suggests a method to break into the holism of belief and meaning
from a prior grasp of the ideal of rationality, the equal priority view
suggests no such route and instead a more encompassing holism. Hence whilst
Davidson denies the possibility of a reductionist account, he does suggest the
possibility of a reductive one reducing meaning not to the physical but to
rational relations. The alternative I have sketched is doubly emergent.
Conclusions
Davidson’s
account of belief and meaning through the thought experiment of radical
interpretation presents a principled account of intentionality in this sense.
It offers an answer to the question: what justifies the description of a state
as meaning-laden. The answer is that it plays a role within radical
interpretation: the project of making sense of speech and action against the
Constitutive Ideal of Rationality. Davidson uses this to argue against the
reduction of the mental to the physical and hence against reductionism, in
Nagel’s phrase. But the simplest way to think of the thought experiment,
encouraged by Davidson’s own presentation, is, nevertheless, reductive:
reducing the mental to the rational.
The
equal priority view of meaning and rational norms sketched above suggests a
more complex picture. Interpretation is still structured by respect of rational
norms or ‘oughts’ but these are augmented by grasp of meanings. Further, some
aspects of rationality are not universal. They require a special design of mind
for their conception and detection. And hence an articulation of what it is
like to have our kind of mind is an articulation from within \a particular
grasp of the world. And hence it is couched in terms which are both higher
order but also local.
This
view, however, raises a question about the nature of philosophical inquiry.
Reductive, and sometimes reductionist, approaches to complex concepts provide a
model for philosophical clarification. Fodor’s argument for reductionism,
quoted above, can serve as a manifesto for philosophical naturalism. Complex
concepts can be fitted into a broader conception of nature and thus rendered
unmysterious by reducing them to more basic constituents. But the equal
priority view just sketched suggests no such method. Reduction to the physical
world at best plays no role in the account of meaning or, at worst, is ruled
out by a Davidsonian a priori argument. Even the connection to rationality
provides no theory-neutral entry for thinking about meaning. Instead, the
account is pitched within the phenomena it aims to clarify, highlighting
internal constraints. In accord with Nagel’s suggestion for emergence, the
connections are all higher order. But unlike Nagel’s account, no attempt is
made to connect this to the world outside meaning except for its role in radical
interpretation. This prompts the question of the kind of philosophical insight
such an account can give. It can only address an audience of those with
appropriate eyes to see and ears to hear. I suggest that this a puzzle for an
emergentist account and suggests a paradox. The account can only be grasped by
those who seem to have no need of it.
Acknowledgement
This
paper was written whilst a fellow of the Institute for Advanced Study, University
of Durham. My thanks both to the IAS, Durham and the University of Central Lancashire
for granting me research leave.
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