ABSTRACT ‘Open texture’ is the property of concepts or terms that they are not fully defined with regard to unexpected questions. Even though it is a ubiquitous phenomenon, there is no consensus on which concepts are subject to open texture. I present three equivalent definitions of open texture, connecting the concept to the notions of analyticity and algebraicity. I show that the claim that a concept is open-textured is equivalent to the claim that (...) the class of analytic sentences using it can be changed, which in turn is equivalent to the claim that its definition is not algebraic. While this equivalence is interesting on its own, with it I can show the extent of open texture: all concepts that are not algebraically defined mathematical concepts are open textured. Finally, I show that this has unfortunate consequences for attempts to provide a foundation of mathematics. (shrink)

The purpose of this article is to explore the extent to which mathematics is subject to open texture and the extent to which mathematics resists open texture. The resistance is tied to the importance of proof and, in particular, rigor, in mathematics.

In this article, I apply the notion of open texture to the moral domain. I argue that moral concepts can exhibit open texture, and that recognising this can yield several explanatory advantages. To begin, I describe the notion of open texture, a type of indeterminacy some of our concepts seem to exhibit. I mention Friedrich Waismann’s original discussion of the notion, but particularly draw upon a recent exposition by Fenner Tanswell. Second, I provide some (...) examples of ways certain moral concepts could be open-textured and suggest that some of our concepts that seem to have undergone change may have exhibited open texture in the past. These include the concepts of “murder”, “racism” and “stealing”. Next, I examine the implications for moral theory more generally, suggesting that the approach is very ecumenical; a wide range of normative theories and meta-ethical views are compatible with open-textured moral concepts. Finally, I consider the theoretical advantages of understanding some of our moral concepts as open-textured. Specifically, I argue that this view provides a new way of understanding faultless disagreements, a more plausible moral epistemology, and can be helpful foraccommodating intuitions about moral verdicts from different cultures. (shrink)

Open texture is a kind of semantic indeterminacy first systematically studied by Waismann. In this paper, extant definitions of open texture will be compared and contrasted, with a view towards the consequences of open-textured concepts in mathematics. It has been suggested that these would threaten the traditional virtues of proof, primarily the certainty bestowed by proof-possession, and this suggestion will be critically investigated using recent work on informal proof. It will be argued that informal proofs (...) have virtues that mitigate the danger posed by open texture. Moreover, it will be argued that while rigor in the guise of formalisation and axiomatisation might banish open texture from mathematical theories through implicit definition, it can do so only at the cost of restricting the tamed concepts in certain ways. (shrink)

Many of the terms of our language, such as “jar”, are open-textured in the sense that their applicability to novel objects is not entirely determined by their past usage. Many others, such as the verbs “use” and “have”, are schematic in the sense that they have only a very general meaning although on any particular occasion of use they denote some more particular relation. The phenomena of open texture and schematicity constitute a sharp challenge to referential semantics, (...) which assumes that every non-logical term has a definite extension. A different, non-referential approach to formal semantics defines truth as relative to a context and defines contexts as built up from exclusively linguistic entities. For any given utterance of a sentence, there will be one of these contexts that pertains to it. In this framework, open texture and schematicity can be understood as consequences of the complex nature of the pertaining relation between contexts and utterances. (shrink)

In recent times, the exponential growth of sequenced genomes and structural knowledge of proteins, as well as the development of computational tools and controlled vocabularies to deal with this growth, has fueled a demand for conceptual clarification regarding the concept of function in molecular biology. In this article, we will attempt to develop an account of function fit to deal with the conceptual/philosophical problems in that domain, but which can be extended to other areas of biology. To provide this account, (...) we will argue for three theses: (1) some authors have confused metatheoretical issues (about the meaning and application criteria of terms) with metaphysical ones (about teleology); this led them to (2) look for explicit definitions of “function”, in terms of necessary and sufficient criteria of application, in order to make the concept of function eliminable; however, (3) if one leaves metaphysical worries aside and focuses on functional attribution practices, it is more adequate to say that the concept of function has an open texture. That is, that a multiplicity of application criteria is available, none of which is sufficient nor necessary to attribute a function to a trait, and which only in concert form a clear picture. We distinguish this thesis from some usual forms of pluralism. Finally, we will illustrate this account with a historical reconstruction of the ascription of a water transport function to aquaporins. (shrink)

In this paper, I argue that it is possible to understand Waismann’s notion of open texture through the paradigm of prototype theory stemming from cognitive linguistics. Indeed, prototype theory conceives concepts as functioning according to a prototype whose concrete application remains indeterminate and flexible. Prototype theory entails thus the possibility that cases that challenge the familiar use of a concept may be encountered in experience, which is precisely at stake with the notion of open texture. At (...) the same time, prototype theory explains the creative dimension of human language that is also mentioned by Waismann: human language is creative precisely because its concepts are flexible and have subsequently the capacity of expressing new types of experience. This new perspective on the notion of open texture presents a double interest. First, it allows highlighting the innovative scope of this notion, since it shows that it has the potential to challenge traditional theories of concepts, which consider concepts as a set of characteristics. Second, it opens the possibility for an extension of the notion of open texture to most if not to all concepts. Several research works have been carried out in this direction. Reconsidering open texture through prototype theory offers a new theoretical tool for this purpose: proving that other, non-empirical concepts also function according to prototypes would indeed prove that open texture is an essential feature of most if not all concepts. (shrink)

In this paper, we will survey the different uses of the term algorithm in contemporary legal practice. We will argue that the concept of algorithm currently exhibits a substantial degree of open texture, co-determined by the open texture of the concept of algorithm itself and by the open texture inherent to legal discourse. We will substantiate our argument by virtue of a case study, in which we analyze a recent jurisprudential case where the first (...) and second-degree judges have carved-out contrasting notions of algorithm. We will see that, thanks to our analysis of the open texture of the notion of algorithm in legal language, we can make sense of the different decisions taken by the judges as different contextually-determined sharpenings of the concept of algorithm. Finally, we will draw some general conclusions concerning the use of technical terms in legal instruments that address new technologies, such as the EU AI Act. (shrink)

I track the origin in Wittgenstein's work of Waismann's concept of open texture and compare their related ideas. Although Waismann published his work on open texture before the publication of Wittgenstein's Philosophical Investigations, he had access to drafts of that work and to other writings of Wittgenstein and heard him present related ideas. A key example of his is closely derived from Wittgenstein's work. We shall see advantages of Wittgenstein's ideas over Waismann's. Waismann does not satisfactorily (...) distinguish semantic from epistemic points; he seems to think that drawing boundaries is done only by definitions; he unjustly sees open texture as the possibility of vagueness, which he problematically conceives as a fluctuating use of a word, and more. In all these respects, Wittgenstein is more precise in his characterisation of the idea. Accordingly, we better follow Wittgenstein in our use of the concept of open texture. (shrink)

This edited collection covers Friedrich Waismann's most influential contributions to twentieth-century philosophy of language: his concepts of open texture and language strata, his early criticism of verificationism and the analytic-synthetic distinction, as well as their significance for experimental and legal philosophy. -/- In addition, Waismann's original papers in ethics, metaphysics, epistemology and the philosophy of mathematics are here evaluated. They introduce Waismann's theory of action along with his groundbreaking work on fiction, proper names and Kafka's Trial. -/- Waismann (...) is known as the voice of Ludwig Wittgenstein in the Vienna Circle. At the same time we find in his works a determined critic of logical positivism and ordinary language philosophy, who anticipated much later developments in the analytic tradition and devised his very own vision for its future. (shrink)

ABSTRACT The traditional view of propositional content presupposes that there is a privileged classification of token representations that partitions them with respect to sameness of content. I argue that there is no such thing: we utilize multiple distinct standards of sameness of content, none of which is privileged. My argument is based on the existence of semantic underdetermination. Plausibly, we use expressions (e.g. ‘sandwich’) that do not have determinate extensions and that are open to precisification in multiple directions. This (...) gives rise to indefinitely many possible cases of content fission, where a semantically underdetermined token is identified as having the same content as two tokens that are precisified in opposite ways. Content fission requires recognizing a huge variety of legitimate notions of sameness of content. (shrink)

The article is based on an observation that there are significant and non-arbitrary similarities between two, seemingly quite distant, theories that address the problem of linguistic categorization. One is the theory of open texture put forward by a prominent legal philosopher, Herbert L.A Hart. The other is the theory of prototypes, originated from psychological research by Eleanor Rosch and developed by cognitively-oriented linguists, most notably Charles Fillmore, George Lakoff, and Ronald Langacker. Firstly, the origins of the open (...) texture theory are presented, including the discussion of Friedrich Waismann's and Ludwig Wittgenstein's ideas and their impact on Hart's theory. Secondly, Hart's theory of open texture is examined, based on several articles and his masterpiece: The Concept of Law (Oxford: Oxford University Press 1961). Thirdly, a brief introduction to the prototype theory is provided, focusing on its reception in Cognitive Linguistics. Fourthly, a comparison of both theories is presented, including a sketch of a broader philosophical and historical background, as well as a detailed analysis of similarities and dissimilarities between them. The comparison results in a conclusion that, on linguistic grounds, the open texture theory can be viewed as an anticipation of prototype theory. Finally, several reservations are made in order to avoid possible confusions and some obvious objections. (shrink)

Open-texture—e.g. vague, ambiguous, under-specified, or abstract terms—in regulatory documents lead to inconsistent interpretation, and are an obstacle to the automatic processing of regulation by computers. Identifying which parts of a legal text fall under open-texture is therefore a necessary requirement to make progress in automating the law. In this paper, we propose that large language models (LLMs) might provide an effective way to automatically detect open-texture in legal texts. We first investigate the obstacles by (...) situating open-texture in the broader literature, and we test the hypothesis using two different LLMs—the proprietary gpt-3.5-turbo and the open-source llama-2-70b-chat—for the task of identifying open-texture in the General Data Protection Regulation. We evaluate their performance by asking 12 annotators to assess their output. We find, overall, that gpt-3.5-turbo overperforms llama-2-70b-chat on F 1 -scores (0.84 vs 0.67), and its high F 1 -score could make it a suitable alternative, or complement, to using human annotators. We also test the sensitivity of the findings against four further LLMs combined with six different prompts, and replicate a finding that there is low agreement between annotators when it comes to the identification of open-texture. We conclude the article by discussing the subjectivity of open-texture, the lessons to draw when testing for open-texture, and the consequences of using LLMs in the legal domain. (shrink)

The purpose of this article is to compare and contrast the underlying accounts of language and linguistic communication in Waismann’s “Verifiability” [1945] and the “Analytic-Synthetic” series [1949]–[1953]. There is some overlap, and the two reinforce each other, but the “Analytic-Synthetic” series presents a more far-reaching view.

This new addition to the series New Studies in Practical Philosophy edited by W. D. Hudson is a study of deontic moral judgment, in particular of moral concepts which embody standards for the assessment of claims to right or wrong actions. Three main theses are quite clearly stated. The first thesis concerns the distinctive character of the moral point of view which is irreducible to either logical or factual considerations. The second thesis is that moral judgments claim interpersonal validity in (...) the sense that the speaker makes the implicit claim that every reflective agent who considers the judgment "ought to agree" with the judgment as a correct one. The third thesis pertains to the moral disagreement. It is maintained that moral disagreements are "in principle" decidable, not by way of deductive subsumption under the criteria governing the uses of moral concepts, but by a method of inquiry analogous to that of scientific inquiry involving the use of hypothesis. The author acknowledges his debt to Arthur Prior, J. Kovesi, and M. Polanyi. The book is good in raising questions on the relation between moral inquiry and scientific inquiry, the significance of the open texture of moral terms and its relation to ethical argumentation, and the problem of reconciling differences of moral beliefs in the setting of their connection with nonmoral beliefs.—A. S. C. (shrink)

An important challenge when creating automatically processable laws concerns open-textured terms. The ability to measure open-texture can assist in determining the feasibility of encoding regulation and where additional legal information is required to properly assess a legal issue or dispute. In this article, we propose a novel conceptualisation of open-texture with the aim of determining the extent of open-textured terms in legal documents. We conceptualise open-texture as a lever whose state is impacted (...) by three types of forces: internal forces (the words within the text themselves), external forces (the resources brought to challenge the definition of words), and lateral forces (the merit of such challenges). We tested part of this conceptualisation with 26 participants by investigating agreement in paired annotators. Five key findings emerged. First, agreement on which words are open-texture within a legal text is possible and statistically significant. Second, agreement is even high at an average inter-rater reliability of 0.7 (Cohen’s kappa). Third, when there is agreement on the words, agreement on the Open-Texture Value is high. Fourth, there is a dependence between the Open-Texture Value and reasons invoked behind open-texture. Fifth, involving only four annotators can yield similar results compared to involving twenty more when it comes to only flagging clauses containing open-texture. We conclude the article by discussing limitations of our experiment and which remaining questions in real life cases are still outstanding. (shrink)

Across his writings, Friedrich Waismann articulates his notion of “open texture” by contrasting it with a phenomenon he calls “vagueness”, claiming that while vague terms fluctuate in their actual usage, open terms may be stable, and that while vagueness can be “remedied” through the provision of more precise rules, open texture is ineliminable. He qualifies this contrast by stating that open texture is “something like possibility of vagueness”, i.e. that open terms can (...) always come to fluctuate in their actual usage despite previous periods of stability. Due to his use of the examples “pink” and “heap” there is a strong temptation to read Waismann as claiming that open texture is the possibility of that vagueness that forms the foundation of Sorites paradoxes, i.e. that open texture is the possibility of something like “degree” vagueness. I argue that this temptation is a mistake. As his own examples of open texture make evident, open texture cannot be the possibility of degree vagueness in particular. Indeed, once we pay attention to his many illuminating examples of various semantic indeterminacies, we find instead, I argue, that open texture is the possibility of no form of vagueness as we understand the notion today. Instead, open texture emerges more plausibly as the possibility of polysemy. (shrink)

H. L. A. Hart and the "Open Texture" of Language tries to clarify the writings of both Hart and Friedrich Waismann on "open texture". In Waismann's work, "open texture" referred to the potential vagueness of words under extreme (hypothetical) circumstances. Hart's use of the term was quite different, and his work has been misunderstood because those differences were underestimated. Hart should not be read as basing his argument for judicial discretion on the nature of (...) language; primarily, he was putting forward a policy argument for why rules should be applied in a way which would require that discretion. (shrink)

This paper develops a unified formal framework for understanding open texture. Building on Kit Fine’s specification space approach, I formalise three distinct accounts: open texture as perpetual openness, as freedom to diverge rationally, and as defeasibility. I show that these formalisations can come apart, while constraints on admissible precisifications create entailment relations between them. I then illustrate the framework’s utility by applying it to Horty’s Reason Model of legal precedent. Finally, the framework highlights a principled difference (...) between open texture and vagueness: whilst supervaluationist approaches to vagueness assume that vague predicates admit complete precisifications that preserve penumbral connections, predicates exhibiting perpetual openness preserve penumbral connections only in limited cases. (shrink)

Just about every theorist holds that vague terms are context-sensitive to some extent. What counts as ?tall?, ?rich?, and ?bald? depends on the ambient comparison class, paradigm cases, and/or the like. To take a stock example, a given person might be tall with respect to European entrepreneurs and downright short with respect to professional basketball players. It is also generally agreed that vagueness remains even after comparison class, paradigm cases, etc. are fixed, and so this context sensitivity does not solve (...) the problems with vague terms. In this paper, I briefly sketch the main features of my broadly contextualist account of vagueness, that of the late Ruth Manor, and that of Agustín Rayo, showing how the three accounts relate to, and reinforce, each other, noting a seeming difference. A key item used to articulate my own view is David Lewis's notion of conversational score. This is used to track which borderline cases have been called in the course of a conversation. Manor alludes to Lewis's notion of accommodation, a key aspect of the kinematics of conversation, and Rayo invokes Stalnaker's notion of common ground. I'll show how the conversational score could be employed to develop and extend their views, showing how vague terms, as they construe them, are (or can be) deployed in conversation, consistent with both the underlying indeterminacy of the terms and normal communicative goals. To help develop all three views further, I invoke Craige Roberts's notion of Retrievability, a tool developed to show how definites, such as definite descriptions, singular pronouns, and proper names, are deployed in conversation, in a Lewis-style scorekeeping framework. This, I think, is exactly the right way to understand conversations in what Manor calls non-sorities situations and, to invoke my own view, in sorites situations as well. (shrink)

The goal of this paper is to develop a normative inferentialist account of open texture, inspired mainly by Robert Brandom (1994; 2000). At the level of metasemantics, open texture is explained by the fact that meaning is grounded in social normative practices that are themselves situated, plural, and contingent. While they are sufficiently stable to enable and sustain coordination, practice-based norms become unsettled in the face of disruptive or unexpected circumstances. At the level of semantics, (...) class='Hi'>open texture is explained by the fact that inferential norms are always incomplete and potentially incoherent. On the resulting view, open texture appears not just as a genuine phenomenon, but as a ubiquitous feature of concepts that pertains to the very nature of linguistic norms: there is a continuous spectrum between determinacy and indeterminacy, settled norms and unsettled norms. Open texture is visible only when norms become unsettled in the face of novelty and a creative resolution is needed in order to decide how to “go on”. In providing this account, I also reconstruct the historical and theoretical lineage connecting Waismann’s notion of open texture, Wittgenstein’s rule-following considerations, and Brandom’s normative inferentialism, showing that Brandom not only systematizes Wittgenstein’s view of meaning but also develops Waismann’s distinctive insights, such as the non-monotonicity of non-deductive rules of inference. (shrink)

The appearance in 1945 of the idea of the open texture of empirical concepts, which anticipated Friedrich Waismann’s thesis of a many-level-structure of language, led to a re-evaluation of “context”. It widens the sense of context that we are accustomed to mentioning as being Wittgenstein’s conception of meaning in his later philosophy. The new idea Waismann brought into the landscape is how to “clarify the context”, which is in a way a very non-Wittgensteinian question as well as an (...) “explanation of context”, where open texture plays a key role. But despite the amount of literature about open texture, this idea of Waismann is still not properly understood. Open texture must be situated as an obstacle to exhaustiveness of definition for internal reasons not only because of unforeseen conditions that could always arise in the future, but also by virtue of an a priori aspect of the texture of concepts. Thus, the main goal of this paper is to propose an interpretation of open texture as an immanent property of a concept, that is, as something that is underlying its nature. (shrink)

Beyond the obvious technical difficulties, human attempts to communicate with hypothetical Extra-Terrestrial Intelligences also present a number of philosophical puzzles. After all, an alien intelligence is likely the closest thing to a Wittgensteinian lion humanity could ever encounter. In this paper I advance a new challenge for the feasibility of communication with extra-terrestrials. The problem I raise is a practical problem that falls out of the history and philosophy of mathematics and the implementation of METI projects—specifically, the semiprime self-decryption schema (...) of the Drake Pictures message strategy. The Drake Pictures strategy presumes that aliens share the concept ‘prime number’ with us, as understanding that concept is necessary to decrypt our message. However, if the concept ‘prime number’ exhibited open texture at any point in its history, it could have developed in a different direction than it did in our history. If that is so, an alien could have the concept ‘prime number’ and still not be capable of decrypting our messages. I argue that this new problem is more trenchant than previous arguments in both the philosophy and SETI literature, such as applications of the aforementioned Lion argument and other concerns about the possibility of long-range communication without the assumption of shared concepts. (shrink)

In this paper we discuss a view of the Machine Learning technique called Explanation-Based Learning (EBL) or Explanation-Based Generalization (EBG) as a process for the interpretation of vague concepts in logic-based models of law.The open-textured nature of legal terms is a well-known open problem in the building of knowledge-based legal systems. EBG is a technique which creates generalizations of given examples on the basis of background domain knowledge. We relate these two topics by considering EBG''s domain knowledge as (...) corresponding to statute law rules, and EBG''s training example as corresponding to a precedent case. (shrink)

Kripke, argued like this: it seems possible that E; the appearance can't be explained away as really pertaining to a "presentation" of E; so, pending a different explanation, it is possible that E. Textbook Kripkeans see in the contrast between E and its presentation intimations of a quite general distinction between two sorts of meaning. E's secondary or a posteriori meaning is the set of all worlds w which E, as employed here, truly describes. Its primary or a priori meaning (...) is the set of all w such that if w is actual, then E is true. "Conceivability error" occurs when a primary possibility is mistaken for a secondary one. Textbook Kripkeanism is rejected on the grounds that it makes meaning too modal and modality too much a matter of meaning. (shrink)

This paper examines how the Barthesian difference between écrivains et écrivants can help analyse H.L.A. Hart’s Open Texture of the law. By comparing literary and judicial interpretation, one is able to better understand how lawyers, judges, and legislators can better interpret, use, and draft legislation and case law. In using concrete examples of legislation with regard to the phrase “cruel and usual”, this paper evaluates different interpretive techniques, uncovering key differences. In particular, it compares what implications the Death (...) of the Author would have on legislation that may be considered as vague, or open-ended. Could this mean the Death of the Legislator? What kind of impact may this have on a democracy’s authority? Ultimately, it is suggested that Barthe’s interpretive literary theories are undesirable when it comes to deciphering legislation. Indeed, more concrete and structured approaches are needed. (shrink)

In this chapter, I reconstruct and interpret Mary Hesse’s work on scientific language from 1952–1961. I begin by looking at her criticisms of views that hold theoretical concepts and statements are made meaningful by reduction or translation into phenomenal concepts and statements. The shortcomings Hesse identifies with these views inform her positive account of scientific language, which pays close attention to the ways scientists talk about and use models. I highlight three aspects of Hesse's account: (1) her use of Friedrich (...) Waismann’s notion of open texture; (2) the role she thinks models drawn from more familiar experience play in making theories intelligible; and (3) her claim that the relationship between the theoretical and phenomenal statements of our theories involves interpretation rather than translation. I then offer preliminary remarks about Hesse’s use of history in developing this account. Finally, I close with a very brief suggestion about the continuity between Hesse’s early use of open texture and the later parallels she draws between metaphors and models. (shrink)

Planning problems arise in law when an individual (or corporation)wants to perform a sequence of actions that raises legal issues. Manylawyers make their living planning transactions, and a system thathelped them to solve these problems would be in demand.The designer of such a system in a common-law domain must addressseveral difficult issues, including the open-textured nature of legal rules,the relationship between legal rules and cases, the adversarial nature ofthe domain, and the role of argument. In addition, the system's design (...) isconstrained by the fact that the intended users are lawyers, and its operation and output must be convenient for lawyers to use.In this article, I describe a system called CHIRON that I have developed to explore solutions to these issues. This system develops simple plans from representations of statutes and cases in the domain of United States personal income tax planning. (shrink)

In the following, I will explore the significance of the threat and challenge open texture can pose to analyticity. I take it that this challenge is very serious but has not been taken seriously enough so far. I will first discuss in some detail (Sect. 1) whether and, if yes, how there still can be necessary or sufficient conditions for some open textured concept or predicate expressing that concept. It turns out that the idea of synonymy does (...) not apply in any straightforward, bivalent way to predicates expressing such a concept. The same holds for the idea of analyticity if it is explained via the idea of synonymy. All this does not mean that there is no tenable conception of analyticity without indeterminacy left (Sect.2). This discussion will also lead to a distinction between different levels of open texture: open texture can be iterated and spread across a system of concepts. The general conclusion is not that the analytic-synthetic distinction cannot be upheld but rather that, given how pervasive open texture is, there might be so few analytic truths that the distinction turns out to be much less significant than perhaps assumed. I end by raising some further questions for further inquiry. An appendix indicates further reasons, independent of open texture, to doubt that there are many analytic truths at all. (shrink)

In this chapter, I reconstruct and interpret Mary Hesse’s work on scientific language from 1952–1961. I begin by looking at her criticisms of views that hold theoretical concepts and statements are made meaningful by reduction or translation into phenomenal concepts and statements. The shortcomings Hesse identifies with these views inform her positive account of scientific language, which pays close attention to the ways scientists talk about and use models. I highlight three aspects of Hesse’s account: (1) her use of Friedrich (...) Waismann’s notion of open texture; (2) the role she thinks models drawn from more familiar experience play in making theories intelligible; and (3) her claim that the relationship between the theoretical and phenomenal statements of our theories involves interpretation rather than translation. I then offer preliminary remarks about Hesse’s use of history in developing this account. Finally, I close with a very brief suggestion about the continuity between Hesse’s early use of open texture and the later parallels she draws between metaphors and models. (shrink)

It is a commonly raised argument against the family resemblance account of concepts that there is no limit to a concept's extension. An account of family resemblance which attempts to provide a solution to this problem by including both similarity among instances and dissimilarity to non-instances has been developed by the philosopher of science Thomas Kuhn. Similar solutions have been hinted at in the literature on family resemblance concepts, but the solution has never received a detailed investigation. I shall provide (...) a reconstruction of Kuhn's theory and argue that his solution necessitates a developmental perspective wchich builds on both the transmission of taxonomies between generations and a progressive development through history. (shrink)