Classifying is a fundamental operation in the acquisition of knowledge. Taxonomic theory can help students of cognition, evolutionary psychology, ethology, anatomy, and sociobiology to avoid serious mistakes, both practical and theoretical. More positively, it helps in generating hypotheses useful to a wide range of disciplines. Composite wholes, such as species and societies, are “individuals” in the logical sense, and should not be treated as if they were classes. A group of analogous features is a natural kind, but a group of (...) homologous features is not. Imposing hypotheses justified only on the basis of nominalist, realist, phenomenalist, or conceptualist metaphysics upon the neurophysiology of organisms or upon the causes of behavior exemplifies the “psychologist's fallacy” of William James. Levels should be distinguished from their members and from classes of levels, and the ontological status of entities ranked at levels should be made clear. It is important not to confuse such categories as substance and process with one another. Several genetical terms, such as “gene” and chromosome,” are even more equivocal than has been realized. Discussions about units of selection, behavior, and thinking suffer from the ambiguity of a “unit of” an entity. An important source of misunderstanding about natural selection is the habit of treating it as an “agent”: in an important sense, natural selection does not “act” at all. (shrink)

Contemporary behavioral and brain scientists consider the existence of so-called basic emotions in a similar way to the one described by Erickson for so-called basic tastes. Commenting on this analogy, I argue that similar basic problems are encountered in both perspectives, and I suggest a potential nonbasic solution that is tested in emotion research (i.e., the appraisal model of emotion).

A numerical classification was performed on 69 elements with 54 chemicaland physicochemical properties. The elements fell into clusters in closeaccord with the electron shell s-, p- andd-blocks. The f-block elements were not included forlack of sufficiently complete data. The successive periods ofs- and p-block elements appeared in an ovalconfiguration, with d-block elements lying to one side. Morethan three axes were required to give good representation of thevariation, although the interpretation of the higher axes is difficult.Only 15 properties were scorable for (...) the noble gases, but despite thepaucity of properties reflecting chemical reactivity, analysis of the 69elements on these properties still showed the major features seen fromthe full set. (shrink)

This study will focus on the differences in the way that Roman Paganism and Christianity organize systems of beliefs. It rejects the theory that “beliefs” have no place in the Roman religion, but stresses the differences between Christian orthodoxy, in which mandatory dogmas define group identity, and the essentially polythetic nature of Roman religious organization, in which incompatible beliefs could exist simultaneously in the community without conflict. In explaining how such beliefs could coexist in Rome, the study emphasizes three main (...) conceptual mechanisms: polymorphism, the idea that gods could have multiple identities with incompatible attributes, orthopraxy, the focus upon standardized ritual rather than standardized belief, and pietas, the Roman ideal of reciprocal obligation, which was flexible enough to allow Romans to maintain relationships simultaneously with multiple gods at varying levels of personal commitment. (shrink)

Four ordering systems have been used most frequently in taxonomy: (1) special purpose classifications, (2) downward classifications (identification schemes), (3) upward or grouping classifications (traditional), and (4) Hennigian phylogenetic systems. The special properties of these four systems are critically evaluated. Grouping classifications and phylogenetic systems have very different objectives: the former the documentation of similarity and closeness of relationship, the latter of phylogeny. Both are legitimate ordering systems.

At least three different issues are commonly referred to by the term “the species problem”: one concerns the necessary properties of species, a second the processes responsible for the existence of species, and a third methods for inferring species limits. Solutions have recently been proposed to the first two problems, which are conceptual in nature (the third is methodological). The first equates species with metapopulation lineages and proposes that existence as a separately evolving metapopulation lineage be considered the only necessary (...) property of species. The second views the species category as a cluster concept and proposes that no single process or set of processes be considered necessary for the existence of species. Although these two solutions have been portrayed as being in conflict, they are, in fact, highly compatible. Moreover, the proposals in question clarify the problem concerning methods for inferring the limits of species, which has for a long time been confused with the problem concerning the necessary properties of species. Together these proposals provide the opportunity for biology to move beyond debates about the definition of the species category and focus on estimating the boundaries and numbers of species as well as studying the diverse processes involved in their origin and persistence. BioEssays 27:1263–1269, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

This paper analyses the traditionally recognized dependence between observation statements and theories. The analysis proceeds by working out the interrelationship between classification systems and theoretical frameworks. Cuvier's and Darwin's theories are used as examples to illustrate this issue. The second part of the paper develops a model designed to give an account of the historical development of this interrelationship. It is argued that the interdependence is not circular and that it is an integral part of scientific research. It is suggested (...) that an interdependence of the type reflected in the model can be helpful in evaluating research programmes in the history of all the sciences. (shrink)

We review different studies of the Periodic Law and the set of chemical elements from a mathematical point of view. This discussion covers the first attempts made in the 19th century up to the present day. Mathematics employed to study the periodic system includes number theory, information theory, order theory, set theory and topology. Each theory used shows that it is possible to provide the Periodic Law with a mathematical structure. We also show that it is possible to study the (...) chemical elements taking advantage of their phenomenological properties, and that it is not always necessary to reduce the concept of chemical elements to the quantum atomic concept to be able to find interpretations for the Periodic Law. Finally, a connection is noted between the lengths of the periods of the Periodic Law and the philosophical Pythagorean doctrine. (shrink)

In the present article I have surveyed several approaches to modeling the clinical diagnostic process. I have argued that at this point of the field's development, logics which simulate the reasoning patterns and knowledge base of expert clinicians represent research programs that are most likely to succeed. No logic of diagnosis has yet attained the status of being definitive; in spite of striking progress much more research and testing is required. On the basis of various existing logics, I have attempted (...) to articulate a number of desiderata which an ideal diagnostic logic should satisfy. In spite of these criticisms, I would maintain that programs such as MYCIN and INTERNIST have already matured to the point where they are useful both in consultations and in teaching diagnostic reasoning. (shrink)