Unification, explanation, and the composition of causes in Newtonian mechanics

William Whewell's philosophy of scientific discovery is applied to the problem of understanding the nature of unification and explanation by the composition of causes in Newtonian mechanics. The essay attempts to demonstrate: (1) the sense in which ‘approximate’ laws (e.g. Kepler's laws of planetary motion) successfully refer to real physical systems rather than to (fictitious) idealizations of them; (2) why good theoretical constructs are not badly underdetermined by observation; and why, in particular, Newtonian forces are not conventional and (3) how empiricist arguments against the existence of component causes, and against the veracity of the fundamental laws, are flawed.     

Species concepts,process analysis,and the hierarchy of nature

Species figure prominently in all biological studies, but what a species actually is and how we recognize it in practice is still a much-debated issue. Present discussion revolves around five major species concepts: the biological, the evolutionary, the cladistic, the recognition and the phylogenetic concepts. Each of these species notions has its theoretical and practical problems. One important point that has emerged from recent discussions on the ontological status of species is that there is a tension between species concepts based on interbreeding and those based on genealogy, and that practical application of these two kinds of concept may give rise to incompatible results. Species recognized by one species concept appear to be essentially different entities compared with species demarcated by another. However, these different species may all represent real and objective entities in nature. What we perceive as a species depends on the evolutionary processes that we have made objects of our research. Some of these processes are between entities of the genealogical hierarchy of nature, while other processes relate to nature's ecological hierarchy. It is essential that our species concept should be adjusted to the focal level of our research program, thereby taking into full account the two process hierarchies of nature.     

Kant,causation and laws of nature

In the Second Analogy, Kant argues that every event has a cause. It remains disputed what this conclusion amounts to. Does Kant argue only for the Weak Causal Principle that every event has some cause, or for the Strong Causal Principle that every event is produced according to a universal causal law? Existing interpretations have assumed that, by Kant’s lights, there is a substantive difference between the two. I argue that this is false. Kant holds that the concept of cause contains the notion of lawful connection, so it is analytic that causes operate according to universal laws. He is explicit about this commitment, not least in his derivation of the Categorical Imperative in Groundwork III. Consequently, Kant’s move from causal rules to universal laws is much simpler than previously assumed. Given his commitments, establishing the Strong Causal Principle requires no more argument than establishing the Weak Causal Principle.     

Models, scientific realism, the intelligibility of nature, and their cultural significance

In this article, I will view realist and non-realist accounts of scientific models within the larger context of the cultural significance of scientific knowledge. I begin by looking at the historical context and origins of the problem of scientific realism, and claim that it is originally of cultural and not only philosophical, significance. The cultural significance of debates on the epistemological status of scientific models is then related to the question of ‘intelligibility’ and how science, through models, can give us knowledge of the world by presenting us with an ‘intelligible account/picture of the world’, thus fulfilling its cultural-epistemic role. Realists typically assert that science can perform this role, while non-realists deny this. The various strategies adopted by realists and non-realists in making good their respective claims, is then traced to their cultural motivations. Finally I discuss the cultural implications of adopting realist or non-realist views of models through a discussion of the views of Rorty, Gellner, Van Fraassen and Clifford Hooker on the cultural significance of scientific knowledge.     

Kant and the nature of matter: Mechanics,chemistry, and the life sciences

Kant believed that the ultimate processes that regulate the behavior of material bodies can be characterized exclusively in terms of mechanics. In 1790, turning his attention to the life sciences, he raised a potential problem for his mechanically-based account, namely that many of the operations described in the life sciences seemed to operate teleologically. He argued that the life sciences do indeed require us to think in teleological terms, but that this is a fact about us, not about the processes themselves. Nevertheless, even were we to concede his account of the life sciences, this would not secure the credentials of mechanics as a general theory of matter. Hardly any material properties studied in the second half of the eighteenth century were, or could have been, conceived in mechanical terms. Kant's concern with teleology is tangential to the problems facing a general matter theory grounded in mechanics, for the most pressing issues have nothing to do with teleology. They derive rather from a lack of any connection between mechanical forces and material properties. This is evident in chemistry, which Kant dismisses as being unscientific on the grounds that it cannot be formulated in mechanical terms.     

Occurrence,distribution and nature of neuropeptide Y in the rat pancreas

Summary Significant quantities of a newly discovered peptide, neuropeptide Y, were found in the rat pancreas, where they were localized to nerves in the exocrine parenchyma and around arterial and ductal structures. Although unaffected by surgical parasympathectomy, the periarterial and periductal nerves were abolished by chemical sympathectomy, suggesting that NPY is partially costored with sympathetic transmitters in nerve fibers.     

Occurrence, distribution and nature of neuropeptide Y in the rat pancreas

Significant quantities of a newly discovered peptide, neuropeptide Y, were found in the rat pancreas, where they were localized to nerves in the exocrine parenchyma and around arterial and ductal structures. Although unaffected by surgical parasympathectomy, the periarterial and periductal nerves were abolished by chemical sympathectomy, suggesting that NPY is partially costored with sympathetic transmitters in nerve fibers.     

Biparitate nature of the pituitary gland inAcridotheres tristis,linneaus

Résumé Les oiseaux femelles possèdent une glande pituitaire plus grande que celle des mâles. La glande est couverte entièrement par les couvertures meningées. Deux types d'aciophiles, un basophile violet et PAS positif, et puis une cellule chromophobe ont été observés. Les lobes céphaliques et la caudale sont separés par un toron de tissu connectif, d'un caractère inconnu jusqu'ici dans la biparitate de la glande pituitaire des oiseaux. Les secretions colloidales de caractère basique sont nombreux dans la pars glangularis et dans la zona tuberalis.     

Structuralism and the conformity of mathematics and nature

Structuralists typically appeal to some variant of the widely popular ‘mapping’ account of mathematical representation to suggest that mathematics is applied in modern science to represent the world’s physical structure. However, in this paper, I argue that this realist interpretation of the ‘mapping’ account presupposes that physical systems possess an ‘assumed structure’ that is at odds with modern physical theory. Through two detailed case studies concerning the use of the differential and variational calculus in modern dynamics, I show that the formal structure that we need to assume in order to apply the mapping account is inconsistent with the way in which mathematics is applied in modern physics. The problem is that a realist interpretation of the ‘mapping’ account imposes too severe of a constraint on the conformity that must exist between mathematics and nature in order for mathematics to represent the structure of a physical system.     

Chemical reductionism revisited: Lewis, Pauling and the physico-chemical nature of the chemical bond

The wave-mechanical treatment of the valence bond, by Walter Heitler and Fritz London, and its ensuing foundational importance in quantum chemistry has been traditionally regarded as the basis for the argument that chemistry may be theoretically reduced to physics. Modern analyses of the reductionist claim focuses on the limitations to achieving full reduction in practice because of the approximations used in modern quantum chemical methods, but neglect the historical importance of the chemical bond as a chemical entity. This paper re-examines these arguments with a study of the development of the valence bond by chemist Gilbert Lewis within a chemically autonomous framework, and its extension by Linus Pauling using Heitler and London’s methods. Here, we see that the chemical bond is best described as a theoretical synthesis or physico-chemical entity, to represent its full interdisciplinary importance from the philosophical and historical perspectives.     

The ever-growing complexity of the mitochondrial fission machinery

The mitochondrial network constantly changes and remodels its shape to face the cellular energy demand. In human cells, mitochondrial fusion is regulated by the large, evolutionarily conserved GTPases Mfn1 and Mfn2, which are embedded in the mitochondrial outer membrane, and by OPA1, embedded in the mitochondrial inner membrane. In contrast, the soluble dynamin-related GTPase Drp1 is recruited from the cytosol to mitochondria and is key to mitochondrial fission. A number of new players have been recently involved in Drp1-dependent mitochondrial fission, ranging from large cellular structures such as the ER and the cytoskeleton to the surprising involvement of the endocytic dynamin 2 in the terminal abscission step. Here we review the recent findings that have expanded the mechanistic model for the mitochondrial fission process in human cells and highlight open questions.     

Moses Maimonides and Judah Halevi on order and law in the world of nature,and beyond

The concept of order, expressed by a number of forms of the Arabic root n.z.m., was of paramount importance in the natural philosophy of medieval Jewish thinkers, far more important than the related concept of law. Moses Maimonides walked a very tight rope between the order that is present in the cosmos, and which testifies to its intelligent Creator, and some minor streaks of apparent disorder, which indicate that the universe is not an eternally self-maintaining entity ruled only by necessity. Judah Halevi was mostly concerned with hierarchical levels of increasing order: a basic orderliness, which describes the cosmos, and a higher level of order, which applies to the Jewish people.     

Histochemical nature of the motor endplate

Zusammenfassung Die Enzyme und Produkte der motorischen Endplatte in der Skelettmuskulatur werden nach der Doppelfärbung mit Cholesterinesterase untersucht. Dabei erweist sich die Succinodehydrogenase in der Endplatte als stark aktiviert. In der Endplatte der neurogenen, atrophischen Muskelfasern ist sie jedoch vermindert.     

Peace with nature,or plants as indicators to the loss of humanity

Summary 1)Peace with nature means that human relations with other beings are controlled constitutionally within a community to which not only mankind belongs. Constitutionally restricted and in this sense non-violent, human domination is legitimate. 2) What we are allowed to do depends on who we are. Mankind is the species in which nature emerges to express herself in language, art and reason, and in doing so she moves herself forward with us. 3) How we should relate ourselves to nature also depends on our understanding of nature. Nature basically is acting nature, or creative power, and in this sense equally is the nature of the beings of nature. 4) Some artifacts are more natural and correspond to peace with nature better than others which are unnatural and violate peace with nature. Also in our fellow world, and even apart from man's influence, nature is whatought to be. 5) The technologically less advanced countries should not repeat the mistakes of the industrialized countries. The traditional pattern of industrial economy cannot be generalized to all peoples and violates peace with nature. 6) Plants are not only most sensitive indicators to environmental pollution but to the loss of humanity as well.