Das Problem der Asymmetrie des Protoplasmas bedarf einer kritischen Besprechung, die der Formulierung einer Reihe grundlegender Fragen, die in erster Linie einer weiteren experimentellen Bearbeitung bedürfen, förderlich sein kann. Vor allem muss hier mit der Terminologie begonnen werden. Man muss unterscheiden: die Dissymmetrie, als Eigenschaft des individuellen Moleküls ein sich mit dem Urbild nicht deckendes Spiegelbild zu besitzen, welche Eigenschaft bei einem bestimmten Niveau der Kompliziertheit der räumlichen Architektur des Moleküls eintritt, und, andererseits, die Asymmetrie als Eigenschaft der Gesamtheit der (...) Moleküle, die in der Abwesenheit der Gleichheit der rechten und linken dissymmetrischen Formen in diesen Gesamtheiten besteht. Für den Biologen bietet die Asymmetrie der molekulären Gesamtheiten insofern Interesse, als sie eine spezifische Eigenschaft des Protoplasmas ist und bei allen dissymmetrischen Stoffen fehlt, die in den irdischen Prozessen unabhängig von der Tätigkeit lebender Wesen entstehen. Hier können folgende grundlegende Fragen gestellt werden: 1. Welcher Art ist der deskriptive Aspekt der Asymmetrie des Protoplasmas? Für welche Komponenten des Protoplasmas ist die Asymmetrie der molekularen Gesamtheiten bei den verschiedenen Vertretern des Tier- und Pflanzenreiches obligatorisch und für welche nicht? 2. Welcher Art ist die physiologische Bedeutung der Asymmetrie des Protoplasmas, und auf welche Weise wird dieser spezifische Zustand aufrechterhalten? 3. Wie kann man sich im Lichte aller dieser Daten die Entstehung der Asymmetrie des Protoplasmas vorstellen?Die asymmetrische Architektur des Protoplasmas läuft im Grunde darauf hinaus, dass das Protoplasma aus Vertretern einer bestimmten Reihe „natürlicher” Antipoden aufgebaut ist. Hierdurch findet eine genaue Fixiertheit des die räumlichen Eigenschaften des Stoffes charakterisierenden Parameters statt. Diese Fixiertheit ist eine wichtige Bedingung für die Verwirklichung der feinen protoplasmatischen Koordinationen. Von allgemeinerem Standpunkt aus ist die Fixiertheit des räumlichen Parameters ein Spezialfall des bekanntenClaude Bernard'schen Gesetzes: „La fixité du milieu intérieur est la condition de la vie libre”.Im Artikel werden zahlreiche Angaben eingehend besprochen, die es gestatten zu behaupten, dass eine Reihe spezieller und tiefer Anpassungen in der physiologischen Organisation der Zelle die vom thermodynamischen Standpunkt unvermeidliche Razemisation des Protoplasmas verhindern, und den spezifischen Zustand der Asymmetrie des Protoplasmas aufrechterhalten. Im Lichte dieser Angaben kann die Entstehung der Asymmetrie des Protoplasmas mit Hilfe der Theorie der natürlichen Zuchtwahl erklärt werden. Der asymmetrische Zustand des Protoplasmasystems verleiht seinem Besitzer eine Reihe biologischer Vorzüge im Vergleich mit dem razemischen Zustand.Le problème de l'asymétrie du protoplasma mérite un examen critique. Cela pourrait aider à formuler une série de questions fondamentales exigeant en premier lieu une étude expérimentale ultérieure. À commencer par la terminologie, on doit distinguer d'une part la dissymétrie, propriété de la molécule individuelle de posséder une image non superposable, qui apparaît à un niveau déterminé de complexité dans l'architecture spatiale de la molécule, et d'autre part, l'asymétrie comme une propriété des ensembles de molécules, représentant le manque dans ces ensembles de l'égalité de forme dissymétriques de droite et de gauche. Pour le biologiste, l'asymétrie des ensembles moléculaires est d'un intérêt particulier, en ce qu'elle présente une propriété spécifique du protoplasma, et qu'elle manque dans toutes les substances dissymétriques, qui se forment au cours des processus terrestres, indépendamment de l'activité des êtres vivants. On peut poser ici trois questions principales: 1. Quel est l'aspect descriptif de l'asymétrie du protoplasma? Quels sont les composants protoplasmiques pour lesquels l'asymétrie des ensembles moléculaires est obligatoire, et ceux pour lesquels elle ne l'est point, chez les divers représentants du règne animal et du règne végétal? 2. Quelle est la valeur physiologique de l'asymétrie protoplasmique, et de quelle manière cet état spécifique se maintient-il? 3. Comment, à la lumière de ces données, peut on se figurer l'origine de l'asymétrie du protoplasma?Dans l'essentiel, l'architecture asymétrique du protoplasma se ramène au fait que celui-ci est construit avec les représentants d'une série déterminée d'antipodes „naturels”. Par cela même il y a là un état de fixité précise du paramètre, qui caractérise les propriétés spatiales de la matière. Cet état de fixité est une condition importante pour la réalisation des délicates coordinations protoplasmiques. Á un point de vue plus général, l'état de fixité du paramètre spatial constitue un cas particulier de la proposition bien connue deClaude Bernard: „La fixité du milieu intérieur est la condition de la vie libre”.Dans le présent article on discute en détail les faits nombreux qui permettent d'affirmer que dans l'organisation physiologique de la cellule, une série d'adaptations spéciales profondes empêchent la racémisation du protoplasma, inévitable au point de vue thermodynamique, et maintenant l'état asymétrique spécifique du protoplasma. Éclairée ainsi par les faits, l'origine du protoplasma asymétrique peut s'expliquer à l'aide de la théorie de la sélection naturelle. L'état asymétrique du système protoplasmique, par comparaison avec l'état racémique, accorde à son possesseur nombre d'avantages biologiques. (shrink)

Does action always arise out of desire? G. F. Schueler examines this hotly debated topic in philosophy of action and moral philosophy, arguing that once two senses of "desire" are distinguished - roughly, genuine desires and pro attitudes - apparently plausible explanations of action in terms of the agent's desires can be seen to be mistaken. Desire probes a fundamental issue in philosophy of mind, the nature of desires and how, if at all, they motivate and justify our actions. At (...) least since Hume argued that reason "is and of right ought to be the slave of the passions," many philosophers have held that desires play an essential role both in practical reason and in the explanation of intentional action. G. F. Schueler looks at contemporary accounts of both roles in various belief-desire models of reasons and explanation and argues that the usual belief-desire accounts need to be replaced. Schueler contends that the plausibility of the standard belief-desire accounts rests largely on a failure to distinguish "desires proper," like a craving for sushi, from so-called "pro attitudes," which may take the form of beliefs and other cognitive states as well as desires proper. Schueler's "deliberative model" of practical reasoning suggests a different view of the place of desire in practical reason and the explanation of action. He holds that we can arrive at an intention to act by weighing the relevant considerations and that these may not include desires proper at all. (shrink)

Listening to someone from some distance in a crowded room you may experience the following phenomenon: when looking at them speak, you may both hear and see where the source of the sounds is; but when your eyes are turned elsewhere, you may no longer be able to detect exactly where the voice must be coming from. With your eyes again fixed on the speaker, and the movement of her lips a clear sense of the source of the sound will (...) return. This ‘ventriloquist’ effect reflects the ways in which visual cognition can dominate auditory perception. And this phenomenological observation is one what you can verify or disconfirm in your own case just by the slightest reflection on what it is like for you to listen to someone with or without visual contact with them. (shrink)

People act for reasons. That is how we understand ourselves. But what is it to act for a reason? This is what Fred Schueler investigates. He rejects the dominant view that the beliefs and desires that constitute our reasons for acting simply cause us to act as we do, and argues instead for a view centred on practical deliberation--our ability to evaluate the reasons we accept. Schueler's account of 'reasons explanations' emphasizes the relation between reasons and purposes, and the fact (...) that the reasons for an action are not always good reasons. (shrink)

Tracing a central theme of Plato's Republic , G. R. F. Ferrari reconsiders in this study the nature and purpose of the comparison between the structure of society and that of the individual soul. In four chapters, Ferrari examines the personalities and social status of the brothers Glaucon and Adeimantus, Plato's notion of justice, coherence in Plato's description of the decline of states, and the tyrant and the philosopher king—a pair who, in their different ways, break with the terms of (...) the city-soul analogy. In addition to acknowledging familiar themes in the interpretation of the Republic —the sincerity of its utopianism, the justice of the philosopher's return to the Cave—Ferrari provocatively engages secondary literature by Leo Strauss, Bernard Williams, and Jonathan Lear. With admirable clarity and insight, Ferrari conveys the relation between the city and the soul and the choice between tyranny and philosophy. City and Soul in Plato's Republic will be of value to students of classics, philosophy, and political theory alike. (shrink)

We formulate a discrete quantum-mechanical precursor to spacetime geometry. The objective is to provide the foundation for a quantum mechanics that is rooted exclusively in quantum-mechanical concepts, with all classical features, including the three-dimensional spatial continuum, emerging dynamically.

This book offers the first comprehensive introduction to wave scattering in nonstationary materials. G. F. Roach's aim is to provide an accessible, self-contained resource for newcomers to this important field of research that has applications across a broad range of areas, including radar, sonar, diagnostics in engineering and manufacturing, geophysical prospecting, and ultrasonic medicine such as sonograms. New methods in recent years have been developed to assess the structure and properties of materials and surfaces. When light, sound, or some other (...) wave energy is directed at the material in question, "imperfections" in the resulting echo can reveal a tremendous amount of valuable diagnostic information. The mathematics behind such analysis is sophisticated and complex. However, while problems involving stationary materials are quite well understood, there is still much to learn about those in which the material is moving or changes over time. These so-called non-autonomous problems are the subject of this fascinating book. Roach develops practical strategies, techniques, and solutions for mathematicians and applied scientists working in or seeking entry into the field of modern scattering theory and its applications. Wave Scattering by Time-Dependent Perturbations is destined to become a classic in this rapidly evolving area of inquiry. (shrink)

The immunology of falciparum malaria, the lethal type of human malaria, has been transformed by two developments. First, a culture system for the asexual blood stages of Plasmodium falciparum.1 Secondly, the cloning and expression of genes coding for a large number of the protein antigens of this malaria parasite over the past two years. Data on proteins, protein antigens and epitopes of P. falciparum supplied by gene cloning techniques have been supplemented by monoclonal antibody approaches, peptide synthesis, and high‐resolution immunochemistry.

Initially, we perceive an indefinite extension imprecisely, a spread C ; this perception can be visual, aural, or tactile.

This paper argues that both teleological and causal concepts are required for explanations of intentional actions. It argues against ‘causalism’, the idea that action explanations are essentially causal. This requires analyzing Mele’s Q-Signals-from-Mars argument that having a purpose and behaving so as to achieve it aren’t sufficient to explain an intentional action. Though Mele’s example shows that external causal interference can defeat the claim that an intentional action has been performed, this is consistent with teleological concepts being required (even if (...) not sufficient) for action explanation. Mele’s example would work even if causalism were true. But causalism is false. Causalism depends on the idea that ‘agents always do what they want’ can be understood as saying agents have mental states, desires, that cause their behavior. But intentional actions involve what agents want only in the sense that actions have purposes, which are not mental states and cannot be the causes of actions. To perform an intentional action is to pursue some purpose in some way. This paper argues that neither the reference to the purpose that explains why the action was performed, nor the causal account of how this purpose was pursued, can be eliminated. (shrink)

In the first part of this paper a logic is defined for propositions whose probability of being true may not be known. A speaker's beliefs about which propositions are true are still interesting in this case. The meaning of propositions is determined by the consequences of asserting them: in this logic there are debates which incur certain costs for the protagonists.The second part of the paper describes the mathematics of the resulting logic which displays several novel features.