Domestic livestock animals and soils must be considered together as part of an agroecosystem which includes plants. Soil sustainability may be simply defined as the maintenance of soil productivity for future generations. There are both positive and negative aspects concerning the role of animals in soil sustainability. In a positive sense, agroecosystems which include ruminant animals often also include hay forage-or pasture-based crops in the humid regions. Such crops stabilize the soil by decreasing erosion, improving soil structure and usually require (...) fewer chemical inputs. Monogastric animal culture is based on an agroecosystem consisting of mainly grain crops. These crops can result in the soil being exposed to water and wind erosion although soil conservation practices that significantly reduce soil losses may be followed. The management of animal manures is not always compatible with soil conservation practices. Careful management of the nutrients in manure is absolutely necessary to avoid nitrate contamination of ground water or phosphorus loading of streams and lakes. In a negative sense, increases in animal livestock populations in association with human population growth are promoting desertification in the arid and semi-arid regions of the world. The key component for a fully compatible and acceptable association between domestic animals and soil productivity is proper management. Careful management of the components of an animal-based agroecosystem is required if soil productivity and environmental quality are to be maintained. Although we have much to learn, technologies are available to move a considerable way towards this ideal state. (shrink)

In this paper I shall venture into an area with which I am not very familiar and in which I feel far from confident; namely into phenomenology. My main motive is not to get away from standard, boring, methodological questions like those of induction and demarcation; but the conviction that a phenomenological account of the empirical basis forms a necessary complement to Popper's falsificationism. According to the latter, a scientific theory is a synthetic and universal, hence unverifiable proposition. In fact, (...) in order to be technologically useful, a scientific hypothesis must refer to future states-of-affairs; it ought therefore to remain unverified. But in order to be empirical, a theory must bear some kind of relation to factual statements. According to Popper, such a relation can only be one of potential conflict. Thus a theory T will be termed scientific if and only if T is logically incompatible with a so-called basic statement b, where b is both empirically verifiable and empirically falsifiable. In other words: T is scientific if it entails ¬b; where b, hence also ¬b, is an empirically decidable proposition. (shrink)

Despite the periodic table having been discovered by chemists half a century before the discovery of electronic structure, modern designs are invariably based on physicists’ definition of periods. This table is a chemists’ table, reverting to the phenomenal periods that led to the table’s discovery. In doing so, the position of hydrogen is clarified.

It has been maintained, by both philosophers and modern scientists, that the two domains of discourse of science and of philosophy are disjoint Though admitting that many physicists subscribed to metaphysical principles, it was claimed - by Duhem and Reichenbach among others - that the scientist's philosophical convictions play, or should play, no role in his scientific work. The present paper attempts to refute this separatist view by showing that Einstein's metaphysical realism - coupled with his Platonistic panmathematicism - played (...) a crucial role in his construction of the Relativity Programme and in his criticism of Quantum Mechanics. The article also shows that although Einstein was neither a strict Humean nor a strict Machian, his phenomenalist interpretation of the empirical basis proved to be an antidote against both conventionalist scepticism and Neurath's coherence theory of truth. /// Tanto filósofos como cientistas têm defendido a ideia de que os domínios discursivos da Ciência e da Filosofia seguem caminhos separados. Mesmo admitindo que muitos cientistas subscreveram princípios metafísicos, a ideia tem sido defendida - por Duhem e Reichenbach, entre outros - de que as convicções filosóficas do cientista não desempenham, ou deveriam não desempenhar, qualquer papel no seu trabalho científico. O objectivo do presente artigo é refutar esta visão separatista das coisas mostrando de que modo o realismo metafísico de Einstein - associado ao seu panmatematicismo platónico - desempenhou um papel crucial na sua construção do Programa da Relatividade e nas suas críticas à Mecânica Quântica. O artigo mostra igualmente que embora Einstein não fosse nem um Humeano estrito nem um estrito Macheano, a sua interpretação fenomenalista da base empírica demonstrou ser um antídoto quer contra o cepticismo convencionalista quer contra a teoria da coerência da verdade de Neurath. (shrink)

The Term ‘liberty’ invokes such universal respect that most modern political economists and moralists endeavour to find a conspicuous place for it somewhere in their systems or prescriptions. But in view of the innumerable senses of this term an insistence on some kind of definition prior to any discussion seems to be justified. For our present purposes attention to two particularly conflicting interpretations will be sufficient. These are sometimes called the ‘negative’ and the ‘positive’ notions of Liberty. According to the (...) ‘negative’ notion, my own liberty implies the reduction to a minimum of the deliberate interference of other human beings within the area in which I wish to act. Conversely the absence of liberty, or coercion, is regarded as undesirable because it amounts to the prevention by other persons of my doing what I want. On the other hand, the ‘positive’ sense of the word ‘liberty’ consists in the attainment of self-mastery, or, in other words, the release from the domination of ‘adverse’ influences. This ‘slavery’ from which men ‘liberate’ themselves is variously described to include slavery to ‘nature’, to ‘unbridled passions’, to ‘irrational impulses’, or simply slavery to one's ‘lower nature’. ‘Positive’ liberty is then identified with ‘self-realisation’ or an awakening into a conscious state of rationality. The fact that it is contended that such a state can often be attained only by the interference of other ‘rational’ persons who ‘liberate’ their fellow beings from their ‘irrationality’, brings this interpretation of liberty into open and striking conflict with liberty in the ‘negative’ sense. (shrink)