the gestalt spirit in language and cognition: a critical review of language: a theory of structure...

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Pergamon New Idem in Psychol. Vol. 12, No. 2, pp. 183-191. 1994 Copylight D 1994 Elsevier Science Ltd Prmted in Great Britain. All rights resewed 0732-I 18X/94 $7.00 0732-118X(94)E0005-M THE GESTALT SPIRIT IN LANGUAGE AND COGNITION A critical review of Language: A Themy of Structure and Use by Per Saugstad (Foreword by Dell Hymes) . Oslo: Solum and New Jersey: Humanities, 1989 JOHN MACNAMARA Department of Psychology, McGill University, Montreal, QC, Canada H3A 1Bl THE DIALECTICAL APPROACH The dominant spirit in psychology is a positivist one and it is difficult for a non- positivist voice to make itself heard. By “positivism” for present purposes I mean an approach that tries to construct the complex from the simple. Such positivism betrays itself in behaviorism; in much of the physiological and low-level work on image processing; in much of the parallel-distributed-processing literature on the psychology of language; in all stage theories of cognitive development which pretend to derive the more complex, from the less complex. In view of the bankruptcy in which positivism finds itself it is gratifying to come across a writer who takes a radically different view. Per Saugstad is a dialectical thinker; he believes that while the whole is illuminated by the scrutiny of the parts, the parts themselves can be properly appreciated only by someone who interprets them in the light of the whole. The dialectical approach can be traced to Hegel, but it is familiar to psychologists through the work of the Gestalt school. That school has given us most of our understanding of visual shape perception, and its principles have recently been extended with signal success to audition by Al Bregman (1990). The dialectical spirit also resides in the axiomatic approach to the primitives of mathematical systems. Since those primitives cannot be defined, their meaning is determined by the system of associated axioms-see David Hilbert’s letter to Frege in Frege (1980, pp. 38-43). Saugstad works out the implications of his dialectical approach for language and he claims that modern linguistics and psycholinguistics suffer from an excess of positivism. This will come as a surprise to some who see Noam Chomsky, to whom both disciplines owe so much, as the great slayer of positivist giants. Recall, however, that Chomsky bases syntax on an intuition of the grammaticality of a single string of words in isolation from its meaning, from its communicative purposes and from the cultural setting in which it performs its communicative functions. Admittedly, Chomsky has always employed semantic evidence in support of syntactic theorizing. Nevertheless, the ambition is to characterize syntax without reference to anything outside syntax-syntax in isolation from everything else. This, you may feel, is not at odds with Saugstad’s dialecticalism, since Chomsky in his syntactic work has no ambition to construct wholes that go beyond syntax. At the same time, he does set 183

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Pergamon

New Idem in Psychol. Vol. 12, No. 2, pp. 183-191. 1994 Copylight D 1994 Elsevier Science Ltd

Prmted in Great Britain. All rights resewed 0732-I 18X/94 $7.00

0732-118X(94)E0005-M

THE GESTALT SPIRIT IN LANGUAGE AND COGNITION

A critical review of Language: A Themy of Structure and Use by Per Saugstad (Foreword by Dell Hymes) . Oslo: Solum and New

Jersey: Humanities, 1989

JOHN MACNAMARA Department of Psychology, McGill University, Montreal, QC, Canada H3A 1Bl

THE DIALECTICAL APPROACH

The dominant spirit in psychology is a positivist one and it is difficult for a non- positivist voice to make itself heard. By “positivism” for present purposes I mean an approach that tries to construct the complex from the simple. Such positivism betrays itself in behaviorism; in much of the physiological and low-level work on image processing; in much of the parallel-distributed-processing literature on the psychology of language; in all stage theories of cognitive development which pretend to derive the more complex, from the less complex.

In view of the bankruptcy in which positivism finds itself it is gratifying to come across a writer who takes a radically different view. Per Saugstad is a dialectical thinker; he believes that while the whole is illuminated by the scrutiny of the parts, the parts themselves can be properly appreciated only by someone who interprets them in the light of the whole. The dialectical approach can be traced to Hegel, but it is familiar to psychologists through the work of the Gestalt school. That school has given us most of our understanding of visual shape perception, and its principles have recently been extended with signal success to audition by Al Bregman (1990). The dialectical spirit also resides in the axiomatic approach to the primitives of mathematical systems. Since those primitives cannot be defined, their meaning is determined by the system of associated axioms-see David Hilbert’s letter to Frege in Frege (1980, pp. 38-43).

Saugstad works out the implications of his dialectical approach for language and he claims that modern linguistics and psycholinguistics suffer from an excess of positivism. This will come as a surprise to some who see Noam Chomsky, to whom both disciplines owe so much, as the great slayer of positivist giants. Recall, however, that Chomsky bases syntax on an intuition of the grammaticality of a single string of words in isolation from its meaning, from its communicative purposes and from the cultural setting in which it performs its communicative functions. Admittedly, Chomsky has always employed semantic evidence in support of syntactic theorizing. Nevertheless, the ambition is to characterize syntax without reference to anything outside syntax-syntax in isolation from everything else. This, you may feel, is not at odds with Saugstad’s dialecticalism, since Chomsky in his syntactic work has no ambition to construct wholes that go beyond syntax. At the same time, he does set

183

184 .I. Macnarnara

out from intuition relating to the grammaticality of a single string and attempts to construct a syntax for a language as a whole. On the face of it this is positivist by Saugstad’s lights.

I am not sure, however, that it really is positivist. Much depends on how one construes syntactic intuition. Chomsky is inclined to situate the intuition of a single string inside the system of psychological rules that guide the production and parsing of sentences in a natural language; and to situate that system against the great system of psychological rules that make the learning of any natural language possible-universal grammar. To my mind Saugstad has not paid sufficient attention to Chomsky’s thinking about intuition (see especially, I,nn~qun~q~- henceforth L-p. 71) .

For all that, there is something not easily dismissed in Saugstad’s reproach. Take his claim that syntax cannot be grasped without reference to communication. The early impact of Chomsky’s work was to conjure up an idea that children learn syntax without benefit of their knowledge of ;he nonlinguistic world. Chomsky had conjectured in Syntactic structures (chap. 9) that syntax is autonomous from semantics; that syntactic rules can and should be stated without reference to any semantic fact. Perhaps autonomy did not imply that semantics is of no use to the learner of syntax and perhaps the growing evidence that it is of use does not refute the hypothesis that syntax is autonomous from semantics. Nevertheless, Chomsky (1986) pushes hard not only the autonomy hypothesis but the view that children can learn the syntax of a simple parental utterance without needing to guess the content that parents are attempting to convey. It is as though Chomsky would explain the basic learning of syntax by an axiomatic approach to syntax, before children have learned the relevant axioms (grammatical rules). Let us look at this more closely, for when we see what is wrong with it we see that the autonomy thesis itself is false and that Saugstdd is right.

The axiomatic approach to meaning works only in areas, like geometq, which can rely on a prior intuition of the area to be axiomatized. Hilbert (1X99/1902, p. 1) states at the very outset of his fi~undations of Ckomrtql that he is engaged in “the logical analysis of our intuition of space.” One might hope for similar success in the analysis of syntax if there is a pretheoretic intuition of syntax. And there is, at least in people who have already learned a mother tongue. The problem is, how do they learn it? There is nothing on its own about the sound or position of a count noun

to evoke in learners’ minds an expression equivalent to “count IIOLUL” Chomsky (1975, p. 32) himself has said as much. But there is no expressing the syntactic rules of a language without using such grammatical labels as “count IIOWI.” So how is the learning of syntax ever to begin? Contrast this with the fact that there is something about certain primitive visual experiences that suggests the notion of distance (implicit in shape), which is fundamental to Euclidean geometry. Since there is nothing in a count noun on its own to do the trick, it must be that there is something about the application of count nouns to the nonlinguistic environment that evokes the notion of count noun. In Macnamara (1989) I attempt to specifk the nonlinguistic conditions for the correct application of a count noun. The fundamental idea is that a count noun designates a kind whose extension consists exclusively of atomic members. By ~xxclusi-orly n/omit I mean that an arbitrary division

The Gestalt spirit in language and cognition 185

of a member does not yield two members, and that the combination of two members does not constitute a member. For example, an arbitrary division of a dog does not yield two dogs and the combination of two dogs does not constitute a dog. Contrast this with water, a mass noun. The theory needs to be extended to handle count nouns, like part, which combine with mass nouns as well as count nouns to yield nonatomic extensions; but we will not delay on the details.

The whole point of this approach is that if we posit in universal grammar (unlearned) such constraints on the application of “count noun”, we can understand how children come by the notion of count noun and how they manage to apply it to words in their mother tongue. The main part of the picture is that when perception presents children with what they construe as atomic elements in some kind, they take a word applied to representatives of the kind as a count noun for that kind. Extra qualifications are needed to help the child distinguish count nouns from proper names. The main point, however, is that without such an approach infants’ success is totally mysterious. But then notice that we have characterized count nouns by semantic means, by reference to the type of extension they have. And we have posited this semantic information in universal grammar. It follows that syntax and semantics are not as autonomous as Chomsky suggests. Saugstad is right that the attempt to abstract syntax completely from semantics must lead to a distortion of syntax and of the theory of how children learn it.

A TYPED THEORY

Saugstad’s most interesting application of the dialectical method is to the opposition between particular and universal. It yields him a typed theory of cognition, which is surely what is required. A little background to make this clear.

Saugstad (pp. 90 ff) points out that the psychological orthodoxy that begins with Locke and descends to us through Hume and Mill offers the following picture of concept formation. Children are confronted with individuals with perceptual properties; their task is to collate the properties in such a way as to form useful categories (or types) of individuals. The picture presupposes that we have access to individuals in cognition prior to specifying a kind (or type) for them. The reason is that to attribute a property to an individual is a cognitive operation, so the picture is a cognitive one. And in the picture we are examining, the types (kinds) result from the process of collating properties. It follows that the picture presupposes cognitive access to untyped individuals. Saugstad holds that this theory is incoherent, since without a kind one has no clue what to count as an individual or as the same individual. To see why consider a few examples. Should we take a shirt to be an untyped individual; or should we count the collar as a separate one, since it is sewn on; or should we take the separate threads or the fibres of the threads as untyped individuals? On the other hand if someone asks us to count the shirts in a room there is no particular difficulty. A kind provides a guide; without one we cannot even begin.

For the question of identity, consider a sculptor who takes a lump of clay and molds it into a statue of Churchill, then squashes it down and remolds it into a statue of Hitler. If in the positivist tradition we hold that the world consists of basically untyped individuals with properties that allow them to be typed, then we ought to

186 J. Macnamara

say that there is an untyped individual Zwhich on one occasion has properties that allow it to be typed as a statue of Churchill and on another as a statue of Hitler. Z, then, is on one occasion the statue of Churchill and on another the statue of Hitler. By the transitivity of identity (expressed here by “is”) it should follow that the statue of Churchill is identical with the statue of Hitler. But this is nonsense. And the nonsense is allowed entry by positing untyped individuals. All is well if we insist that there are two trpe~ involved in the operation, one being lump of clay and the other statue. We must also give up the identity of either statue with the lump of clay; our theory being thoroughly typed requires that the individuals on the left and right of the identity sign belong to the same type for the identity sentence to be well formed. The relation between a statue and the clay of which it is formed must be handled by a relation other than identity, but we will not go into it here-see G. Reyes (1991) and M. Reyes (1988).

These examples help to intimate how deep an intuition Saugstad is following in opting for a typed theory. I might add that it is the same intuition that Russell followed to escape the famous paradox that he discovered in Frege’s set theory. Russell’s ploy was to propose the theory of types. Zermelo implicitly made the same step when he replaced the axiom of abstraction, which gave rise to the paradox, with the axiom of separation. The latter allowed one to form a new set only if its members were already members of another set. Effectively, the new axiom excludes untyped individuals-see Suppes (19’72, chap. 1).

It is difficult to overrate the importance of Saugstad’s general position for cognitive psychology including language learning. It has deep implications for the theory of learning proper names (L p. 105) and common nouns (L p. 103), for the theory of concept formation (L chap. 5), and for the theory of learning the fundamentals of syntax. Saugstad’s position is, of course, at odds with the positivist tradition in psychology which would attempt to base concept formation on access to perceptual properties in untyped individuals, or “bare particulars” as he calls them. Under another name this is the theory of abstraction, which, since it presupposes conceptual access to bare particulars, we now see to be incoherent. Saugstad’s position is vastly superior to the standard psychological one.

If there is a fault in Saugstad’s book it is that he does not take the theory of types far enough. Unless I am mistaken he unwittingly appeals to bare particulars in cognition in his account of common nouns. He says, for example, that a common noun “is defined by its reference to the characteristic, the concept, which determines membership in a category” (L p. 103). What the word “dog” refers to, then, is a set of conditions for membership in the kind dog. Look at this more closely and you will see that it depends on bare particulars. For we must somehow discern creatures independent of the kind dog before we can see if they satisfy the conditions for being a dog. That would not pose a problem, if the individuals to be examined were construed as members of the kind animal. They would not then be bare particulars. We cannot, however, appeal indefinitely to anchoring kinds such as animal relative to dog to save us. For if the individuals to be examined for membership in the kind dog are in the kind animal, and individuals to be examined for membership in the kind animal are in the kind physical object (if there is such a kind) and so on, either we come inevitably to a highest-level kind whose members

The Gestalt spirit in language and cognition 187

belong to no higher kind or the process is an infinite regress. Since an infinite regress is out of the question, it follows that there must, on this way of construing things, be a stock of bare particulars to which the concept for the kind is applied. The only way to escape the regress is to posit bare particulars. And since this would happen at the most comprehensive level, we would be back to a universe of bare particulars; exactly what we set out to avoid. (I owe the general point to Gonzalo Reyes.) What is to be avoided is the claim that there is access in cognition to bare particulars; which does not preclude there being access otherwise, say in perception, to individuals without the requirement to specify a type for the individual.

Elsewhere expressions making an implicit appeal to bare particulars sometimes escape Saugstad. When speaking about the problem of vagueness (p. 91) he asks “should an impression be classified as a tree or a bush?” Obviously an impression of a tree or a bush is neither a tree nor a bush. What Saugstad seems to be trying to ask is “should an object be classified as a tree or a bush?” where “object” is construed as a bare particular.

The root trouble was the view that common nouns refer, in the first instance, to a set of conditions for membership in a kind. All goes well if, instead, we take such nouns as referring to kinds; e.g. the noun “dog” as referring to the kind dog, which consists of all the dogs that ever were, are and will be. The kind dog is an abstract object, not identical with its members; just as a set is an abstract object, not identical with its members. When I say a kind is abstract I mean among other things that it does not change with time and that it plays no part in the causal events that occur in space and time. It is perhaps the abstractness of kinds, in the sense described, that the positivists dimly sensed and instinctively shied away from. It is to Saugstad’s credit that he thinks things through and is unafraid of the consequences.

THE GUIDING ROLE OF PERCEPTION AND COGNITION

Of a piece with his views that syntax and semantics cannot fruitfully be considered in isolation from one another is his view that perception and cognition have a determining, formative, influence on natural languages rather than the other way about. The idea is that perception and cognition constrain natural languages to reflect the structure of perception and cognition rather than that language constrains the form of perception and cognition. This is in obvious agreement with placing certain general cognitive structures in universal grammar (i.e., Chomsky’s construct for constraining natural languages as well as children’s learning of them). For reasons already considered as well as many that might be added (Macnamara, 1986), Saugstad’s position seems both correct and important; though it is at odds with a good deal of the philosophy of language that stems from Wittgenstein’s writing.

Saugstad goes further and brings perception and cognition together since both involve individuals in types: “we never perceive or think about something without attributing it to some category” (p. 84). Since there are no individuals that are not in kinds, it follows that what we perceive and what we think about are individuals in kinds. Saugstad, however, goes beyond this and claims, not only that the individuals we perceive and think about are in kinds but that in order to perceive and think

188 J. Macnamara

about them we must “attribute” them to some category; we must specify a suitable category for them. Moreover, what we see is not “an aggregate of colors and shapes, not an aggregate of sensations, but an object which has a unity” (p. 84).

To see how important this is recall that Franz Brentano (1874/ 1973, pp. 77 ff and 1982, pp. 21 ff) uses “reference to something as an object” as the criterion for distinguishing the mental from the physical: or, as we might say today, the intentional from the physical (or physiological). Though Brentano struggled all his life to make this intuition clear he never, to my mind, succeeded in doing so satisfactorily. In his insistence on a typed theory, I believe Saugstad furnishes us with a clue that goes some way to solving the puzzle. Consider that the types (kinds) are abstract objects which stand aside from causality. Since they play a crucial role in all intentional states, it follows that Brentano’s distinction can be construed as one between states in which types play a constitutive role and states in which they do not. Not that the objects in physiological states are untyped, but that the types are not constitutive of them. To see this more clearly consider an example: a rock topples off a shelf and shatters a glass jar. In the actual event there is just the rock with its mass acted upon by gravity falling and shattering the jar. Though the objects and forces involved are typed, the types play no part in the event. Turn now to a cognitive state representing the event. It might be expressed in the words “The rock fell and shattered the glass jar.” Here the words “rock” and ‘liar” denote types and those types are essentially involved in the interpretation of the sentence. This, if I am not mistaken, was what Brentano was seeking to express.

If this is correct, is Saugstad entitled to bring perception and cognition so close together? Certainly perception is a source of knowledge, which means that perceptual states give rise to intentional ones. But is there not a causal story to be told about perception that falls short of the intentional? Is there not, for example, a story of light being structured by surfaces, in turn structuring retinal reactions and being processed by the brain in its own way prior to the process issuing in an intentional state? The question I am asking is whether the theory of perception should include the intentional state or not. Since, as Brentano said, intentional states are distinct from physical (and physiological) ones, it seems natural to keep the theory of perception distinct from that of cognition. There is, I might add a very old tradition of doing so. Plato does so in the Theaetetusand Aristotle in the De Anima

(Book 3, chap. 3). This is not in the least to take from Saugstad’s insistence that the objects of perception are typed and that true sentences reporting perception refer to the types. As Saugstad says, if I see a tree, the object I see is a member of the type tree. There is no question of perceiving bare particulars.

What is at issue is the uncoupling of theories of perception and cognition. The case for doing so can be made more compelling still. A single perceptual object, say a dog, permits of several distinct conceptualizations-as a dog, a poodle, a mammal, an animal. A single conceptualization, say as a dog, can be sustained by distinct perceptions of an object-from the front, from the back, from the side. It follows that the theories of perception and cognition are mutually autonomous.

Now we are in a position to solve a problem that Saugstad fails to solve, namely the learning of kinds through contact with some of their members. We have seen Saugstad make a surreptitious appeal to bare particulars in his remark that

The Gestalt spirit in language and cognition 189

sometimes we do not know whether to classify something as a bush or a tree. But, you may ask, are we not always in that position when confronted with an object for which we do not know a kind; and if so must we not choose between an inability to learn new kinds from contact with their members and the shunned bare particulars? The uncoupling of the theories of perception and cognition is the first step towards an escape. For we now see that the kinds play no part in the theory of perception; only in the theory of cognition. We can, then, claim perceptual access to individuals without the need to specify a kind. What is ruled out is conceptual access to an individual without specifying a kind. (The general point here emerged in conversation with Gonzalo and Marie Reyes.)

Saugstad makes a number of moves related to the connection between language and thought that I consider odd and unnecessary. He rejects the idea of a language of thought on the grounds that a language is essentially implicated with communication and we are not supposed to be able to communicate in the language of thought (p. 62). At the same time he maintains that thought can occur without language. In this he notes he is going against a tradition that includes such redoubtable figures as Herder, Saussure, Frege, Wundt, Quine and Wittgenstein; but he is strengthened in his position by the belief that thought occurs in species other than man, even though they give no sign of commanding a language.

Saugstad’s insistence on the necessity to specify a kind (type) for the objects of thought creates a torsion in connection with his claims of languageless thought. The problem is how to specify a kind. He seems to believe, with Vygotsky, that the mind can do so by means of signs in isolation from language (p. 27). I find this discomforting, because the one way known to us of referring to kinds is through common nouns. But common nouns are constituents of sentences and perform their function only in a sentence. Saugstad, to my mind, makes matters worse by concluding that “Sentences . . . are the products of the use of language and should not be regarded as forming part of language” (p. 124). This, I think, is just unfortunate. He seems to have been led to this position by an insistence on more primitive instruments of thought than sentences and these he finds in signs, which he takes as the precursors of words. This allows him to construe sentences as some sort of inessential superstructure on words; though he does try to strengthen his position by saying that while words are “the unit of meaning”, sentences are “the unit of information” (p. 120). In favor of all this he presents some rather unimpressive arguments based on the one-word utterances of babies and the one- word utterances of adults. The trouble is that he has no good grounds to discourage our belief that such one-word utterances of babies and adults as “dog” are truncated versions of such sentences as “This is a dog” or “Is this a dog?” And he has no argument whatever that there are means other than common nouns for referring to kinds. I find this whole aspect of Saugstad’s argument tortuous and unconvincing; and strangely nondialectical. For surely there is an obvious dialectical relation between words and sentences such that we should not stress one at the expense of the other.

In keeping with his general stance on language is Saugstad’s view that words are assigned meaning originally through languageless thought and perception (L chap. 6). Sentences presuppose words and if there is no language of thought it follows

190 J. Macnamara

that early words are learned in nonlinguistic environments. This position is undialectical, because if any dialectical stance is justified it is that a word’s status as a word, as a word of a grammatical category, as a word with a particular meaning is determined by a sentence, even though the determining sentence is determined in part by the word that it determines. This dialectical stance can be turned against Saugstad. There is no reason whatever for children to take a sound to be a word, unless they associate the sound with an expressive intent. They must take the sound as being applied to something. They must locate a likely perceptual object and attach the word to it in the appropriate manner. Now the word “dog”, even as applied to a particular dog, does not refer to the dog. It refers to the kind to which the dog belongs. To get it right, children must guess that the word “dog” assigns the perceived individual to a kind called “dog”. But this all entails a sentence. That is unavoidable. The sentence fixes the semantic role of the word, and through the semantic role it fixes, as we have seen, a syntactic role too.

What of thought in animals? I have nothing against conceding thought to them, but I believe the concession presupposes a language of thought. That is, if “thought” as applied to animals is to be understood in anything like the sense it has when applied to people. I find it impossible to understand infants and their development if they are denied thought, but again I posit in them a language of thought, for reasons I have developed in Macnamara (1982 and 1986). For people with a sense of history I might add that there is nothing new in the notion of a language of thought. It is implicit in Aristotle’s notion of a sense common to the external senses, a sense in which different input senses can communicate. St Augustine in the De Trinitate speaks of a language of the heart which could not be used to communicate with another person. St Thomas Aquinas speaks about a “Verbum mentale,” an expression of the mind. And even so positivistic a thinker as William of Ockham

retained in his Summa logicae the view that there is such a language. I must not, however, end on a negative note. Saugstad’s book is the fruit of long

and deep and independent thought on language and cognition. Out of a massive literature on language and cognition this is perhaps the only book that I could unhesitatingly recommend in the confidence that it will repay prolonged study. Even the small number of rather odd positions that the author takes are well worth thinking through to the roots of the oddness. The field is in the greatest need of contributions that compel us to rethink well-entrenched positions and not to rest content until we have reached the bottom of things. Saugstad’s book is such a contribution.

REFERENCES

Bregman, A. (1990). Audit9 scene analysis. Bradford: MIT Press. Brentano, F. (1874/1972). Psychology from an empirical standpoint. London: Routledge &

Kegan Paul. Brentano, F. (1982). Descriptive Psychologie [Descriptive psychology]. Hamburg: Felix Meiner. Chomsky, N. (1975). Refictions on language. New York: Pantheon. Chomsky, N. (1986). Some observations on language and language learning: Reply to

Macnamara, Arbib and Moore and Furrow. New Ideas in Psychology, 4,363-377. Frege, G. (1980). Philosophical and mathematical correspondence. University of Chicago Press. Hilbert, D. (1899/1902). Thefoundations ofgeometly (Trans. E. J. Townsend). Chicago: Open

Court.

The Gestalt spirit in language and cognition 191

Macnamara, J. (1982). Names for things: A study of human Learning. Bradford: MIT Press. Macnamara, J. (1986). A border dispute: The place of logic in psychology. Bradford: MIT Press. Macnamara, J. (1989). More about principles and parameters. A reply to Chomsky. New Z&as

in Psychology, 7,33-40. Reyes, G. E. (1991). A topos-theoretic approach to reference and modality. NotreDameJournal

of Formal Logic, 32, 359-391. Reyes, M. (1988). A semantics for literary texts. Unpublished doctoral dissertation,

Concordia University, Montreal. Suppes, P. (1972). Axiomatic set theory New York: Dover.

Note: My ideas have benefited greatly from discussions of the issues raised with Michael Hallett, Michael Makkai, Gonzalo Reyes and Marie Reyes. I have also had the good fortune to discuss the issues with Per Saugstad during his visit to Montreal in September 1989. He has also been good enough to comment at length on an earlier version of the review.