16.2451, Review: Semantics: van Lambalgen & Hamm (2005)

[LINGUIST List]

LINGUIST List: Vol-16-2451. Mon Aug 22 2005. ISSN: 1068 - 4875.

Subject: 16.2451, Review: Semantics: van Lambalgen & Hamm (2005)

Moderators: Anthony Aristar, Wayne State U <aristar at linguistlist.org>
            Helen Aristar-Dry, Eastern Michigan U <hdry at linguistlist.org>
 
Reviews (reviews at linguistlist.org) 
        Sheila Dooley, U of Arizona  
        Terry Langendoen, U of Arizona  

Homepage: http://linguistlist.org/

The LINGUIST List is funded by Eastern Michigan University, Wayne
State University, and donations from subscribers and publishers.

Editor for this issue: Lindsay Butler <lindsay at linguistlist.org>
================================================================  

What follows is a review or discussion note contributed to our 
Book Discussion Forum. We expect discussions to be informal and 
interactive; and the author of the book discussed is cordially 
invited to join in. If you are interested in leading a book 
discussion, look for books announced on LINGUIST as "available 
for review." Then contact Sheila Dooley at dooley at linguistlist.org. 

===========================Directory==============================  

1)
Date: 19-Aug-2005
From: Magda Dumitru < magdalena_dumitru at yahoo.com >
Subject: The Proper Treatment of Events 

	
-------------------------Message 1 ---------------------------------- 
Date: Mon, 22 Aug 2005 22:13:13
From: Magda Dumitru < magdalena_dumitru at yahoo.com >
Subject: The Proper Treatment of Events 
 

AUTHORS: van Lambalgen, Michiel; Hamm, Fritz
TITLE: The Proper Treatment of Events
SERIES: Explorations in Semantics
PUBLISHER: Blackwell Publishing
YEAR: 2005
Announced at http://linguistlist.org/issues/16/16-389.html 

Magda Dumitru, unaffiliated scholar

SUMMARY

The volume comes fourth in the series "Explorations in Semantics" 
edited by Susan Rothstein, and dedicated to students and 
researchers in linguistics and philosophy of language. It has three 
parts, the first on linguistic issues ("Time, Events, and Cognition", 
comprising chapters 1, 2, and 3), the second on computational and 
logical formalisms ("The Formal Apparatus", including chapters 4, 5, 
and 6), and the third on their "marriage" ("A Marriage Made in 
Heaven -- Linguistics and Robotics"- chapters 7 through 12). An 
Appendix, "The Basic of Logic Programming", is last to follow.

The semantics of tense and aspect is studied from the vantage point 
of cognitive science (truth and reference are cognitive, not real 
entities; tense and aspect are discussed in terms of goals, actions and 
consequences) and is approached in a fully computational way with 
clear pedagogical intent -- exercises are proposed at the end of 
several chapters, and the reader is addressed directly: "Readers not 
familiar with this notion are advised to read the Appendix first" (p. 
51); "The reader for whom this is all new is advised to read only the 
statements of the theorems and skip the proofs" (p. 58); "the reader 
who is having trouble here is advised to refer back to that section" (p. 
108); "it would be clear (at least to a mathematically inclined reader) 
what to do" (p. 223). An errata, supplementary material (proofs), and 
slides for eventual instructors can be found at  
http://staff.science.uva.nl/~michiell.

Chapter 1 "Time" 
The main question the authors ask is: 'what must our minds be like for 
tensed talk to make sense?'. Their answer is that human minds 
manage to integrate past, present, and future via planning 
(constructing and prioritizing events in memory). Therefore, temporal 
perspective ought to be the main conceptual view on time, from which 
other views (time as duration and time as succession) are derived. 
Goal-plan knowledge can relate past, present, and future when 
constructing narratives (executions of plans toward given goals), for 
instance, via episodic memory -- defined as a "generalized capacity 
for imagining or constructing possible worlds" (p. 13). The authors 
adduce psychological and neurological evidence supporting their 
conclusion.

Chapter 2 "Events and Time" 
The chapter is meant to better define the notion of event, from a 
cognitive point of view: "the basic building block of the human 
construction of time is the event" (p. 15). Semantics, defined as 
cognitive representation of events, must include both temporal and 
non-temporal relations; the latter involve goals and actions 
undertaken to achieve them, as well as cause and effect. An example 
discussed here is the French Passé Simple (PS), which may refer 
either to an event taken as a whole, or to its left and right boundaries. 
The authors further favor the Walker construction of events, instead of 
the Russell-Kamp model, because it is able to better account for the 
semantics of the PS, and because it has other important features: it 
allows for instants to be directed and to mark change, it assumes the 
notion of spacious present, and insures the derivation of continuous 
time from events. Humans individuate events (and hence construct 
time) by using object recognition (by distinguishing figure from ground) 
and by forming goals and plans (the raising of a hand may be part of a 
handshake or of a grasping action).

Chapter 3 "Language, Time, and Planning" 
Language production may be linked to planning via linearization. 
Moreover, planning is instrumental in establishing discursive 
coherence via anaphoric and temporal binding. The authors maintain 
that tense itself should be interpreted in discourse, not in single 
sentences (issue taken to be a counterargument to generativism). An 
example supporting this argument is, again, the French PS, proven to 
introduce events into discourse, which are then ordered thanks to 
world (causal) knowledge. Planning plays an important role in 
semantics: English future tenses involving auxiliaries always encode 
goals; human cognition seems to be goal-oriented, since the perfect is 
future oriented (the reference time lies in the future of the event time --
 following Reichenbach); "Language production can be characterized 
as transforming a semantic structure" (p. 27).

Chapter 4 "Events Formalized" 
The chapter discusses event calculus (EC), a formalism for planning -- 
nonmonotonic (default) reasoning -- involved both in time cognition 
and tensed language. EC requires a first-order logic whose 
vocabulary includes individual objects, real numbers (to represent 
time), time-dependent properties (states and activities), variable 
quantities, and event types (marking the limits of time-dependent 
properties). EC allows for reification/ nominalization (properties may fill 
an argument slot in a predicate); perfect nominalizations are 
temporally related (are modeled as event types), whereas imperfect 
nominalizations are modeled as fluents and are not temporally related. 
EC also allows for predicates to include an explicit parameter for time. 
As for tenses, the past applies to events, whereas progressives apply 
to fluents. Causality, a relation between events, is taken to belong to 
physics and comes in two varieties: instantaneous change and 
continuous change. In instantaneous change, event types (e.g. 
collision) may become event tokens by combining with a time 
parameter. Event types are initiated or terminated by a fluent (fluents 
are time-dependent properties -- sets of intervals including initiating 
and terminating instants; fluents are considered as both functions and 
objects, which may further take a parameter x). Relevant predicates 
are 'Initially', 'Happens', 'Initiates', and 'Terminates'. In continuous 
change (e.g. drinking a glass of wine) the relevant 
predicates 'Trajectory', 'Releases', 'Clipped', 'Declipped', and 'HoldsAt' 
insure that some properties ('f-relevant events') escape the inertia 
specific to the first form of causation; "continuous change occurs due 
to a force, not an event, and hence absence of relevant events does 
not always entail absence of change". The definition of events 
includes the 'Happens' predicate, while the definition of fluents 
includes the 'HoldsAt' predicate. 

The long-standing semantic issue of whether fundamental temporal 
entities should be points or intervals is thus sidestepped; the authors 
maintain that events and fluents, both extended in time yet playing 
different roles in EC, are fundamental temporal entities. Robotics 
needs to derive predictions, and therefore insures situation 
description via axioms (holding for every situation) and scenarios 
(holding for a particular situation). Inertia ought to be defined by a 
suitable logic, working alongside EC and restricting the class of 
models. Computational limitations lead the authors to operate with 
minimal models exclusively (defined as 'closed worlds' including only 
events and causal influenced between events, as specified for a given 
scenario), not with substructures of the 'real', as Discourse 
Representation Theory does, for instance. Developing discourse is 
modeled as a nonmonotonic progression (as a form of planning), 
which accounts for the meaning of the progressive in English and for 
the phenomenon of coercion.

Chapter 5 "Computing with Time and Events" 
"if semantics wants to make contact with the huge psycholinguistic 
literature on language comprehension and production, it had better 
become computational" (p. 49). Accordingly, the authors adopt 
Moschovakis' idea that the sense of an expression identifies with the 
algorithm that computes the denotation of that expression. The 
authors also cite evidence by Mani and Johnson-Laird, according to 
whom uniquely determined cognitive models facilitate the recall of a 
piece of discourse, and hence could be stored in memory. Models 
(which include denotations) are computed by the sense of 
expressions. The semantic theory proposed includes two languages: 
a language of predicates in EC, and a language of constraints 
(formulas). Both languages define a programming language: 
constraint logic programming, which differs from standard logic 
programming in that unification proceeds via equation without 
substitution. The logic program consists thus of a scenario and the 
axioms of EC. A minimal model of the logic program is defined as the 
completion of the program.

Chapter 6 "Finishing Touches" 
Nominalization is taken to be instrumental in the construction of tense 
and aspect, since "nominalized VPs are the basic units of semantic 
computation, in their guise as fluents and events" (p. 71). Montague 
semantics, dynamic semantics, and Davidson's analysis of events are 
all rejected as possible bases for analysis for different reasons: the 
first treats intensions via possible worlds, the second treats 
computation at an abstract level, and the third is not representing "an 
extensional two-sorted first order language in which predicates may 
have a time parameter" (p. 72). Events and fluents, not language 
formulas, are the basic computational entities, since they are involved 
in causal relationships.

Chapter 7 "Aktionsart" 
"Aktionsarten form a continuum, organized around five prototypes, 
rather than a discrete set" (p. 93). An Aktionsart is not "a permanent 
feature attached to a V or a VP" (p. 83), since verbs can be coerced 
into any Aktionsart. Aktionsarten are seen as eventualities(in the 
sense of Emmon Bach) attached to a VP, and defined as a quadruple 
containing an event and up to three fluents. An eventuality determines 
a scenario by specifying the meaning of the elements present in the 
quadruple. Verbs are of the form run(x, t), where x is the subject 
position, and t the time parameter, over which it can be abstracted in 
two ways (as an event type -- which is a function of time, and as a 
fluent -- which is an object), yielding perfect and imperfect nominals. 
Users don't have direct access to the time parameter, yet do have 
direct access to derived event types and fluents, represented 
as "definable finite unions of intervals and points" (p. 88). Tense, 
expressed by the predicates 'Happens' and 'HoldsAt', applies once 
the abstractions obtain. The imperfect paradox is solved by 
dissociating the goal (incremental theme) from the activity leading to 
that goal, which are then fused together in a single event.

Chapter 8 "Tense" 
The formalization proposed for tense makes reference to the concept 
of 'integrity constraints', borrowed from database theory, and 
expressing "obligations and prohibitions that the states of the 
database must satisfy if they fulfill a certain condition" (p. 99); when 
updating a database, care must be taken for these integrity 
constraints to hold under the new circumstances.  Mostly event types 
(hence eventualities viewed perfectively) are located in time (either in 
a given event structure or in their representation as instants or, 
ideally, on the axis of the reals). Reals are needed to represent 
aspect. Cognition works with both event- and instant structure. The 
starting point for representing time is Reichenbach's tripartite structure 
(reference time R, event time E, and utterance time S). R is defined as 
an "integrity constraint formulated in terms of fluents, which typically 
puts constraints upon possible temporal locations of event types, 
including the events [fluents and event types] constructed by 
hierarchical planning" (p. 103). Integrity constraints help define truth 
for tensed sentences, in the sense that sentences are true if the 
integrity constraint is satisfied, and false otherwise. R is taken to be 
fundamental, since it is fixed by an integrity constraint, and represents 
an anchor for E. The (semantic) present tense takes R, E, and S to 
coincide. The past tense situates both R and E before now; it 
operates on an event type (e.g. running, writing, etc.). Unlike the 
perfect, the past tense requires an explicitly established past 
reference point. The past progressive applies to an event fluent and 
does not entail the completion of the event type, unlike the past tense. 
The author's aim is to define tense for each Aktionsart separately; 
however, when applying the progressive to Aktionsarten other than 
activities and accomplishments, the scenario must be extended in 
order to coerce the VP to either an activity or an accomplishment. 
Future events can be conceptualized as events per se, or as goals 
(through the use of the auxiliary 'will', the 'be going to' VP, and the 
futurate progressive).

Chapter 9 "Tense in French: Passé Simple and Imparfait" 
The chapter sketches the semantics of the French Passé Simple and 
Imparfait, as an application of the machinery developed in the 
previous chapters. Of particular interest is the ordering of events in 
time described by the PS; the authors maintain that the ordering can 
be established by computing the meaning of the PS sentences, 
together with world knowledge, and anaphora relations. PS obeys an 
integrity constraint such that an eventuality is represented as 
perfective and located in the past; however, PS itself cannot insure 
ordering relations by itself. As for the Imparfait, it obeys an integrity 
constraint such that it becomes represented as an "anaphoric, 
imperfective past tense" (p. 136). This is supplementary evidence 
against analyzing sentences in isolation.

Chapter 10 "Grammatical Aspect" 
The perfect is taken to belong to the category of grammatical aspect, 
and therefore it "sits uncomfortably between the two stools of tense 
and aspect" (p. 151). The present perfect includes, in its meaning, the 
idea of current relevance of an event, while the reference time is set 
at 'now'. The past perfect either provides a past reference time while 
its consequences still hold, or it is only a past in the past. The integrity 
constraint at work for the present perfect introduces a time at which 
the start event happens. The progressive is coercing an expression 
into either an activity or an accomplishment; moreover, the authors 
argue for a third truth value (indeterminate) for cases such as 
the 'Multiple-Choice Paradox', yet offer no convincing arguments.

Chapter 11 "Coercion" 
Since "Aktionsart is not fully determined prior to the sentence level" (p. 
168), aspectual coercion insures that constructions such as the 
progressive force a VP to change aspectual category. The authors 
describe three types of coercion: additive, subtractive, and cross-
coercion, which mean, respectively, that a given scenario is built (by 
adding a direct object to a verb, for instance), that parts of a scenario 
are deleted, or that parts of a scenario are unified (a constant and a 
parameter, for instance). An interesting issue is the representation of 
nominals: "In our setup, the denotation of a house is as it were 
distributed over the changing partial object, the canonical terminating 
event, and the consequent state whose relations are governed by the 
scenario" (p. 177). In passive sentences, where NPs move to the 
subject position, the nominal may be reinterpreted as a real object 
(and hence adjectives can be applied). The authors assume that 
aspect imposes temporal structure on events and therefore may 
override the Aktionsart of a verb. The process is made possible if one 
interprets Frege's notion of sense as a basis for determining 
reference; otherwise the authors consider events not to have any 
canonical referents in the world. The sense of an expression is its 
associated scenario; one may navigate between the senses an 
expression may have by appealing to coercion.

Chapter 12 "Nominalization" 
Although the authors concede that 'Nominalization is a very 
complicated phenomenon" and that "we can barely scratch the 
surface here" (p. 207), they begin the analysis with a distinction 
Vendler once made, between two kinds of verbs: 'loose containers' 
(e.g. surprised us, is unlikely, is improving), and 'narrow containers' 
(e.g. took place yesterday). Loose containers take both nominal and 
verbal gerunds (corresponding to perfect nominals -- event types -- 
and imperfect nominals -- fluents, respectively), while narrow 
containers take only nominal gerunds. Coercion may explain this 
asymmetry, if it is assumed that there are two kinds of nominals 
(eventive and factive), and that an eventive noun is reinterpreted as a 
factive noun when combined with a loose container. The chapter then 
presents a historical view on the English gerundive system, in order to 
highlight the origins (phonological and morphological processes) and 
function of the verbal gerund (a newer type of gerund that came to 
function alongside the old type -- the nominal gerund). The authors 
agree with theories such as Houston's, according to which verbal 
gerunds (and participles) used to have mostly an adverbial function 
and introduce background information; therefore verbal gerunds are 
taken to introduce fluents. 

The authors then propose a formalized theory of nominalization based 
on Feferman calculus, as follows: a perfect nominal (atemporal) can 
be created from a verb by suppressing its temporal parameter through 
existential quantification. On the contrary, imperfect nominals can be 
internally modified by tense and aspect, since the temporal parameter 
of the underlying verb is abstracted. Interestingly, the actual lexical 
content of perfect and imperfect nominals is of no consequence here. 
Determiners are taken to encode tense; event types in the restrictor 
are related to event tokens in the nuclear scope. Coercion regulates 
both the nominal and the verbal systems, considered to be 
interdependent. The abstract structural representation of perfect and 
imperfect nominals can be enriched with lexical content (determined 
by a scenario) and Aktionsart of underlying verbs; together, they form 
a temporal profile, further interacting with verbal context.

CRITICAL EVALUATION

The volume has important qualities: it is very interesting and thought 
provoking, especially for linguists (although language engineers and 
philosophers may profit as well). It is an attempt at bridging the gap 
between artificial intelligence and linguistics in a consistent way, by 
discussing various core issues, such as time, tense, aspect, verbal 
and nominal categories, and category shifting (coercion). They all 
involve events, in some way or another, hence the title 'The proper 
treatment of events' would seem justified, though less suggestive of 
the wealth of topics discussed throughout the book.

As far as editing is concerned, it looks like the book was prepared for 
publication under considerable constraints of time and space. The 
style is very uneven -- part I anticipates, sometimes in great detail, 
conclusions and implications of the theory to be proposed and 
applications to be discussed later in the book; part II is rather terse, 
since much information is presented in very little space; part III is 
considerably more elaborated, sometimes too much so -- the detailed 
historical account of the English gerund, although very interesting, is 
not justified by the economy of the book, especially since the authors 
seem to bear it in mind -- "Giving the full completion of the program 
would take up too much space" (p. 62); "Unfortunately, for lack of 
space, we will not discuss the very important topic of argument 
structure" (p. 72); "It is however a nightmare from the expository point 
of view to have to work with both an event structure and its 
representation as a continuum" (p. 98), etc. Economy may also be the 
reason for not providing translations for the French example sentences.

Other 'slips' seem to be the result of haste -- sometimes, symbols are 
not defined as soon as they are introduced ('r' at p. 40 is explained at 
p. 72; the 'imperfective paradox', first mentioned at p. 44 is discussed 
at p. 156, etc.), etc.; this little problem could be solved by introducing 
addenda. Typos are rare: "morphologial" (p. 151); "as the long as" (p. 
219), etc.

Psychological and neurological evidence cited mostly in the first 
chapters may be interpreted as supporting the view that humans are 
goal-oriented agents. The authors infer from it that humans ought to 
apply the same cognitive mechanisms when approaching language 
(grammar): "It is then but one step to hypothesize that the linguistic 
coding of time is also driven by the future-oriented nature of our 
cognitive makeup". The 'step' may be very big indeed, since humans 
do not seem to root their goals in the present exclusively 
(Reichenbach's model may not be complex enough for a cognitive 
approach), despite the way future is encoded; also, it is not sure 
whether being future-oriented always means being goal-oriented. 
However, such considerations might link to the assumed linearity and 
first-order approach of the book, and hence may be seen 
as 'necessary evils'.

As for the celebrated "marriage" between linguistics and robotics, it 
does not resemble very much a union, but rather a unification, where 
computation seems to be what all this is about, were it not for integrity 
constraints: sense is defined as an algorithm leading to meaning 
(denotation) as given by a minimal model. Perhaps a detailed 
theoretical discussion here would have been too much to ask from 
such a dense book.

Last but not least, the authors cite a rich bibliography that, together 
with the pedagogical e-tools and the wealth of ideas suggested 
make 'The proper treatment of events' an essential book for linguistics 
students and researchers interested in the latest trends.

REFERENCES

Davidson, D. 1967. The logical form of action sentences. The logic of 
decision and action, ed. by N. Rescher. Pittsburgh, PA, University of 
Pittsburgh Press.

Feferman, S. 1984. Toward useful type-free theories. Journal of 
Symbolic Logic, 49, pp. 75-111.

Frege, G. 1962. Sinn und Bedeutung. G. Frege: Funktion, Begriff, 
Bedeutung. Funf logische Studien, ed. by G. Patzig. Goettingen, 
Vandenhoeck.

Houston, A. 1989. The English gerund: Syntactic change and 
discourse function. Language change and variation, ed. by R. Fasold 
and D. Schiffrin. Amsterdam, Benjamins.

Kamp, H. 1979. Events, instants, and temporal reference. Semantics 
from different points of view, ed. by R. Baeuerle, U. Egli, and A. von 
Stechow, pp. 27-54, Berlin, Springer Verlag.

Mani, K. & P. N. Johnson-Laird 1982. The mental representation of 
spatial descriptions. Memory and Cognition, 10, pp. 181-187.

Moschovakis, Y. 1993. Sense and denotation as algorithm and value. 
Lecture Notes in Logic, ed. by J. Oikkonen and J. Vaananen, Natick, 
MA, A.K. Peters.

Reichenbach, H. 1947. Elements of symbolic logic, London, Macmillan. 

ABOUT THE REVIEWER

Magda Dumitru studies issues in Micro-Semantics, relating to 
definiteness, genericity, tense and aspect.





-----------------------------------------------------------
LINGUIST List: Vol-16-2451