In both biology and the human sciences, social groups are sometimes treated as adaptive units whose organization cannot be reduced to individual interactions. This group-level view is opposed by a more individualistic one that treats social organization as a byproduct of self-interest. According to biologists, group-level adaptations can evolve only by a process of natural selection at the group level. Most biologists rejected group selection as an important evolutionary force during the 1960s and 1970s but a positive literature began to grow during the 1970s and is rapidly expanding today. We review this recent literature and its implications for human evolutionary biology. We show that the rejection of group selection was based on a misplaced emphasis on genes as “replicators” which is in fact irrelevant to the question of whether groups can be like individuals in their functional organization. The fundamental question is whether social groups and other higher-level entities can be “vehicles” of selection. When this elementary fact is recognized, group selection emerges as an important force in nature and what seem to be competing theories, such as kin selection and reciprocity, reappear as special cases of group selection. The result is a unified theory of natural selection that operates on a nested hierarchy of units.
 The vehicle-based theory makes it clear that group selection is an important force to consider in human evolution. Humans can facultatively span the full range from self-interested individuals to “organs” of group-level “organisms.” Human behavior not only reflects the balance between levels of selection but it can also alter the balance through the construction of social structures that have the effect of reducing fitness differences within groups, concentrating natural selection (and functional organization) at the group level. These social structures and the cognitive abilities that produce them allow group selection to be important even among large groups of unrelated individuals.

Reintroducing group selection to the human behavioral sciences

Gru nd legung zur Metaphysik der Sitten

A Study of Concepts

Knowledge in Flux

The fundamental postulate of sociobiology is that individuals exploit favorable environments to increase their genetic representation in the next generation. The data on fertility differentials among contemporary humans are not cotvietent with this postulate. Given the importance of Homo sapiens as an animal species in the natural world today, these data constitute particularly challenging and interesting problem for both human sociobiology and sociobiology as a whole.The first part of this paper reviews the evidence showing an inverse relationship between reproductive fitness and “endowment” (i.e. wealth, success, and measured aptitudes) in contemporary, urbanized societies. It is shown that a positive relationship is observed only for those cohorts who bore their children during a unique period of rising fertility, 1935–1960, and that these cohorts are most often cited by sociobiologists as supporting the central postulate of sociobiology. Cohorts preceding and following these show the characteristic inverse relationship between endowment and fertility. The second section reviews the existing so-ciobiological models of this inverse relationship, namely, those of Barkow, Burley, and Irons, as well as more informal responses among sociobiologists to the persistent violation of sociobiology's central postulate, such as those of Alexander and Dawkins. The third section asks whether the goals of sociobiology, given the violation of its fundamental postulate by contemporary human societies, might not be better thought of as applied rather than descriptive, with respect to these societies. A proper answer to this question begins with the measurement of the pace and direction of natural selection within modern human populations, as compared to other sources of change. The vast preponderance of the shifts in human trait distributions, including the IQ distribution, appears to be due to environmental rather than genetic change. However, there remains the question of just how elastic these distributions are in the absence of reinforcing genetic change.

Social versus reproductive success: The central theoretical problem of human sociobiology

Philosophy, Evolution and Human Nature.

Publisher Summary This chapter examines the relationship between logic, mathematics, and the natural sciences. A constructivist version of a mathematical theory is adequate for all the applications to be made of the theory within natural science. In the overall context of the hypothetico–deductive method in natural science, constructivist logical reasoning is adequate for the applications to be made even of classical mathematics. This chapter sets out a “minimalist” position regarding the correct logic by means of which one may pursue the hypothetico–deductivist method in natural science. It is argued that intuitionistic relevant logic (IR) is adequate. A requirement of reflexive stability is that such an argument should be conducted within the confines of the very logic whose methodological adequacy is to be established. This chapter also addresses an objection in principle that has been raised by John Burgess to the reflexive stability of the argument for IR. The question of the adequacy of constructive methods for hypothetico–deductivism in natural science is examined. The fate of strictly classical theorems of applied mathematics is also discussed in the chapter.

Logic, Mathematics, and the Natural Sciences

Some ideas gain currency as soon as there is a linguistic medium of exchange. Truth is one such. Its role in our intellectual economy is much like that of money in the real one. Canonical warrants to make assertions are like gold bars. Truth-claims are like paper money: promises to produce gold bars on demand. Jim Edwards's helpful analysis of the root of my disagreement with Crispin Wright (see Wright 1992, ch.1; Tennant 1994; and Edwards 1997) prompts me to warn against proliferating derivatives in the anti-realist exchange. To be sure, we must not sell truth short; but we should not short-change the truth-teller either. In S 1 of this note Edwards's criticisms are countered; then in ?2 an argument advanced for the view that Wright's notion of superassertability (once it is properly explicated) has no role to play in the anti-realist's account of empirical discourse.

The Full Price of Truth

This study is in two parts. In the first part, various important principles of classical extensional mereology are derived on the basis of a nice axiomatization involving ‘part of’ and fusion. All results are proved here with full Fregean (and Gentzenian) rigor. They are chosen because they are needed for the second part. In the second part, this natural-deduction framework is used in order to regiment David Lewis’s justification of his Division Thesis, which features prominently in his combination of mereology with class theory. The Division Thesis plays a crucial role in Lewis’s informal argument for his Second Thesis in his book Parts of Classes. In order to present Lewis’s argument in rigorous detail, an elegant new principle is offered for the theory that combines class theory and mereology. The new principle is called the Canonical Decomposition Thesis. It secures Lewis’s Division Thesis on the strong construal required in order for his argument to go through. The exercise illustrates how careful one has to be when setting up the details of an adequate foundational theory of parts and classes. The main aim behind this investigation is to determine whether an anti-realist, inferentialist theorist of meaning has the resources to exhibit Lewis’s argument for his Second Thesis—which is central to his marriage of class theory with mereology—as a purely conceptual one. The formal analysis shows that Lewis’s argument, despite its striking appearance to the contrary, can be given in the constructive, relevant logic IR. This is the logic that the author has argued, elsewhere, to be the correct logic from an anti-realist point of view. The anti-realist is therefore in a position to regard Lewis’s argument as purely conceptual.

Parts, classes and Parts of Classes: an anti-realist reading of Lewisian mereology

Summary

I defend a conventionalist view of logical and (some) mathematical truths against the criticisms of Quine and Stroud. Conventionalism is best formulated by appealing to sense-conferring rules governing important logical and mathematical expressions. Conventional necessity can be understood as arising from these rules in a way that is immune to Quine's and Stroud's criticisms of the earlier formulation of conventionalism, in which stress was incorrectly laid on axiomatic systems of logic.



Resume

Je soutiens, en depit des critiques de Quine et de Stroud, une conception conventionnaliste des verites logiques et de (certaines) verites mathematiques. La meilleure facon de formuler le conventionnalisme est de faire appel a des regies conferant un sens a?on;importantes expressions logiques et mathematiques. La necessite conventionnelle peut etre comprise comme provenant de ces regies par des voies qui ne donnent pas prise aux critiques de Quine et de Stroud ag ľegard de ľancienne formulation du conventionnalisme, dans laquelle ľaccent etait mis, a tort, sur les systemes axiomatiques de la logique.



Zusammenfassung

Gegen Quines und Strouds Kritiken verteidige ich eine konventionalistische Auffassung der logischen und (gewisser) mathematischer Wahrheiten. Der Konventionalismus wird am besten durch Berufung auf bedeutungsstiftende Regeln, die den Gebrauch wichtiger logischer und mathematischer Ausdrucke bestimmen, formuliert. Konventionelle Notwendigkeit kann als von diesen Regeln hervorgebracht verstanden werden – und das zwar auf eine Art, die sie vor Quines und Strouds Anfechtungen schutzen. In der von diesen kritisierten, fruheren Fassung wurde zu unrecht das Gewicht auf axiomatische Systeme der Logik gelegt.

Neil Tennant

Papers

Philosophy, Evolution and Human Nature.

Logic, Mathematics, and the Natural Sciences

The Full Price of Truth

Parts, classes and Parts of Classes: an anti-realist reading of Lewisian mereology

Conventional Necessity and the Contingency of Convention