Roberto De Andrade Martins

Towards the middle of the 18th century, Pierre-Louis Moreau de Maupertuis proposed the “principle of least action” as a fundamental law of physics and as a proof of the existence of God. Samuel König and other contemporary authors criticized Maupertuis’ work. There ensued a fierce discussion concerning this subject, in which Leonhard Euler, the king Frédéric II of Prussia and Voltaire took part. This paper discusses that debate, emphasizing its extrascientific features and analyzing the interests that motivated the actions of the people involved in that episode. Key words: Pierre-Louis Moreau de Maupertuis, François Marie Arouet Voltaire, Johann Samuel König, Frédéric II – king of Prussia, principle of least action, history of physics, scientific controversies.

The sixth chapter of Charles Darwin’s Origin of Species is called “Difficulties of the Theory.” In that part of his work, Darwin reveals some possible objections to his theory and attempts to provide an answer to all of them. Such a chapter was part of the first edition of the Origin of Species; therefore, the difficulties described were not reactions derived from the publication of the book. Instead, friends like Charles Lyell have probably presented some of them. Others can be found in works published before Darwin’s work, such as Natural Theology by William Paley, which argued for creationism and introduced arguments against any natural explanation of the origin of species. Many other problems dealt with in the sixth chapter were born, however, from Darwin’s own internal dialogue, his own initial doubts concerning the theory, and his anticipation of criticism, as one can gather from his manuscripts. This paper describes the main difficulties shown in the sixth chapter of the Origin of Species, providing a more detailed exposition of a few topics, and analyzing Darwin’s defense, in those cases. It also discusses some of the weak points in Darwin’s line of reasoning from a diachronic point of view.

: Suppose a scientist discovers a new, unpredicted phenomenon. How can one ascertain the causes, properties and laws of the phenomenon? How can one plan the investigation of the circumstances that affect the phenomenon, and of the effects that the new phenomenon could produce? If the phenomenon is completely unexpected and does not fit any previous theory, it is impossible to provide a theoretical prediction of its likely properties. In the empiricist tradition, therefore, the recommended method was to investigate all possibilities, because in such cases it is impossible to exclude a priori anything. William Stanley Jevons provided a clear criticism of this method. It is impossible to investigate all possibilities, because they are boundless. Is it then impossible to plan the research of unexpected new phenomena? No. Jevons pointed out an alternative. According to Jevons, a scientist confronting a new, unexpected phenomenon, should compare it to other known phenomena to establish analogies. This comparison should allow the researcher to find out one or several known phenomena similar to the new one. This paper will present and discuss Jevons’ proposal in the context of late 19th century methodology of science. Keywords: scientific method; empirical research; analogy; Jevons, William Stanley.

The focus of this paper is one of James Prescott Joule’s scientific contributions: the laws of heat production by electric currents in conductors. In 1841, the 22 years old Joule published a paper with the title “On the heat evolved by metallic conductors of electricity, and in the cells of a battery during electrolysis” where he presented an experimental study of that phenomenon and proposed two laws that were allegedly supported by his trials. On closer inspection, both his laboratory work and his inferences can be challenged. The emphasis of this article is an attempt to understand Joule’s experimental undertaking, its highpoints and shortcomings, by a detailed analysis of this specific episode and by studying the precedents of his work and subsequent advancements. It is possible to point out several serious deficiencies of that investigation, and Joule’s contemporaries, such as Edmond Becquerel and Heinrich Lenz, did criticize some of his flaws and undertook new experiments to provide a sound basis for those laws. Besides providing a historical examination of that specific episode, this article uses this case study to tackle some features of the nature of science that may contribute to scientific education.

ConclusionThe common assumption that Becquerel had no special reason to study uranium compounds in his search for substances emitting penetrating radiation cannot explain (a) Becquerel's own accounts, which refer to his choice as due to “the peculiar harmonic series of bands”; (b) Becquerel's systematic test of all uranium compounds (and metallic uranium), in contrast to his neglect of other substances; and (c) Becquerel's belief in invisible phosphorescence as an explanation of the radiation emitted by uranium compounds, even after his discovery that non-luminescent and metallic uranium also emit penetrating radiation.By comparing Becquerel's older studies of uranium to his radioactivity research, this paper has presented a reconstruction that can explain all of these points above. According to the historical evidence presented here, it is likely that Becquerel concentrated his attention on uranium and its compounds because the mechanical theory of luminescence opened up the possibility that, precisely in the case of uranium and its compounds, a violation of Stokes's law could occur, and penetrating short-wavelength radiation could be emitted through a special type of phosphorescence.

In his celebrated historic-epistemological work Identité et réalité, Émile Meyerson claimed that the scientific conservation principles were first suggested and accepted for philosophical reasons, and only afterwards were submitted to experimental tests. One of the instances he discussed in his book is the principle of mass conservation in chemical reactions. Meyerson pointed out that several authors, from Antiquity to Kant, accepted the idea of quantitative conservation of matter; and Lavoisier himself was strongly influenced by a priori ideas, using this principle instead of attempting to test it. This paper will review Meyerson’s claim and historic evidence, focusing especially the late nineteenth and early twentieth century, when the principle of mass conservation was tested in highly accurate experiments. Instead of confirming the principle, some of those experiments led to the detection of anomalies. Hans Landolt, for instance, noticed that there were some small violations of the principle. He observed mass variations of about 10−6 in chemical reactions produced in hermetically sealed glass tubes. Since Landolt was a famous chemist, his results produced a strong response. Several researchers repeated his experiments, with different results. Landolt himself improved his experiments, with a balance that could detect mass changes of 10−7. After changes of the experimental procedure, the chemical reactions did not show significant mass changes. There was not, however, any “crucial experiment” “proving” that mass was conserved. The observed anomalies were set aside mainly by theoretical reasons, after the discovery of radioactivity and the development of the theory of relativity.

This paper studies Galileo Galilei’s Trattato della sfera ovvero cosmografia, which was written before 1600. It is a geocentric astronomical treatise that follows the main structure of Johannes de Sacrobosco’s Tractatus de sphæra. This paper analyzes some peculiarities of Galileo’s treatise, comparing it to several other vernacular astronomical works of the sixteenth century and discussing its likely sources. Contrary to previous claims, we argue that Christoph Clavius’ commentary on Sacrobosco’s Sphæra cannot be regarded as its only or main influence. A likely inspiration for Galileo’s treatise is Alessandro Piccolomini’s Sfera del mondo, a work that anticipated several specific features of the Trattato della sfera. This influence is corroborated by Galileo’s copious marginal notes found in a copy of Piccolomini’s book.

From Antiquity to the 19th century it was very common to explain natural phenomena (especially biological ones) through final causes. This paper analyses one of the periods of development of this concept, in Antiquity, with special emphasis upon the contributions of Socrates and Plato. They introduced the idea of an intelligent and beneficial god, who plans the structure of the universe and of all beings in the best possible way. This concept was strongly influential in later periods. RESUMO: Da Antiguidade até o século XIX foi muito comum procurar-se entender os fenômenos naturais (especialmente os biológicos) através de causas finais. Este artigo analisa um dos períodos de formação dessas concepções, na Antiguidade, dando especial atenção às contribuições de Sócrates e Platão. Estes introduzem a ideia de uma divindade inteligente e bondosa, que planeja a estrutura do universo e de todos os seres da melhor forma possível. Essa concepção teve grande influência, no período posterior.

Este trabajo discute si hoy todavía es posible admitir que hay principios a priori que no pueden ser abandonados por la física. La historia indica que ciertas “imposibilidades” filosóficas (como el movimiento, el vacuo y la acción directa a distancia) fueron sucesivamente abandonadas por la física. En el siglo XX, la mecánica cuántica rechazó al determinismo y al principio de simetría. La opinión más común entre los científicos es la de que cuando hay un conflicto entre física y filosofía hay que despreciar a los principios a priori. Sin embargo, hay todavía casos en los cuales es posible negar la posibilidad de determinados objetos físicos que entran en conflicto con nuestros conceptos espaciales. El autor defiende que existen principios a priori válidos en la física, y que su abandono es una deficiencia de determinadas teorías físicas modernas. Tal postura no tiene por consecuencia la negación de tales teorías, pero impone la tarea de complementarlas o interpretarlas de un novo modo para que sean compatibles con los principios filosóficos.

Although historians and philosophers of science usually try to explain the acceptance or rejection of hypotheses or theories by scientists, there are no well definite criteria to evaluate when a scientist accepts or rejects a theory/hypothesis. This work proposes a new method of analysis. The attitudes of scientists towards a theory or hypothesis are classified according to three dimensions (cognitive, instrumental and strategic). This method is exemplified by the study of the attitude of the British naturalist William Bateson (1861-1924) towards chromosome theory. The analysis shows that Bateson never rejected the chromosome theory – a conclusion opposite to most historical accounts. RESUMEN: Los historiadores y los filósofos de la ciencia intentan explicar la aceptación o lo rechazo de determinadas hipótesis ó teorías por los científicos, pero no hay criterios claros que nos permitan decir lo qué es aceptación o rechazo. Este trabajo propone un nuevo método de análisis. Las actitudes de los investigadores son analizadas en relación a tres dimensiones (cognitiva, instrumental y estratégica). El método es ejemplificado por el estudio de la postura del naturalista inglés William Bateson (1861-1924) frente a la teoria cromosómica. El análisis que se realizó permitió verificar que Bateson jamás rechazó la teoría cromosómica, en contrario de lo que la mayoría de los historiadores afirman.

This paper discusses George John Romanes’ (1848-1894) contributions to evolution theory. In his early evolutionary work, Romanes could be regarded as a mere disciple and collaborator of Darwin. Strictly speaking, a follower of Darwin would only attempt to develop and to diffuse Darwin’s ideas, to apply them to new cases, to obtain new evidence for this theory and to answer to problems and objections against Darwin’s theory. However, after working for some time under Darwin’s guidance (for instance, trying to provide an experimental foundation for the hypothesis of pangenesis), Romanes adopted another strategy. As several other so-called Darwinians of the late 19th century, he endeavored to correct and to complement Darwin’s theory, with the introduction of new concepts and hypotheses (especially his “physiological selection”). Romanes’ new attitude might be regarded as an effort to step out of Darwin’s shadow and to exhibit his own brightness. Besides that, Romanes strove to undermine the work of other Darwinians that aimed at similar goals.

O conceito de pseudo-ciência procura identificar propostas que têm uma aparência científica mas que não satisfazem critérios rigorosos de cientificidade. Alguns exemplos muito citados de pseudo-fenômenos estão os fatos alegados pela parapsicologia e pela astrologia. Para caracterizar a pseudo-ciência alguns autores propuseram critérios psicológicos, sociológicos ou metodológicos. O objetivo básico de uma caracterização metodológica dos pseudo-fenômenos é permitir identificar aquilo que parece existir, mas não existe. Trata-se, portanto, de uma distinção essencialmente ontológica. Este trabalho irá descrever várias tentativas de estabelecer critérios desse tipo e mostrará que nenhuma delas é satisfatória. Será apresentada uma abordagem alternativa, compatível com o caráter provisório do conhecimento científico, que permite avaliar a proposta de existência de um novo fenômeno e guiar a pesquisa, sem no entanto permitir concluir se o fenômeno existe ou não.

According to Aristotelian physics, there was a fundamental distinction between natural and violent motion. When the cause of the motion was internal to the moving body, that motion was regarded as natural. Violent motion was supposed to have an external efficient cause. It should stop as soon as this external cause ceased its action. The fall of a body was believed to have an internal cause – the very nature of the heavy body – but the motion of a projectile was supposed to be accidental and a violent one, produced by an external agent and maintained by the continuous action of the air around it. Those distinctions disappeared from physics during the 17th century. Descartes and Newton do not address those problems. However, in Galileo’s thought those distinctions were still present, and they did play a relevant role in his physics. Some central arguments presented by Galileo Galilei in the Dialogues concerning the two chief world systems depended on the characterisation of circular motion as “natural”. Considerations concerning natural or violent motion, circular and straight motions, provided a trap that led Galileo astray to ideas that seem extremely odd, from the point of view of classical mechanics. This article shows how Galileo struggled with those Aristotelian concepts when he tried to understand the nature of the motion of falling bodies.

This paper discusses the possibility of an absolute vacuum - a space without any substance. The motivation of this study is the contrast between most philosophers, up to Descartes, who stated that a vacuum was impossible, and the 17th century change of outlook, when the possibility and effective existence of the vacuum was accepted after the experiments of Torricelli and Pascal. This article attempts to show that, contrary to the received opinion, the acceptance of an ether is preferable to the acceptance of a vacuum for several reasons. First: it is impossible to provide an empirical proof of the non-existence of the ether; second, an absolute vacuum is unthinkable; third, the ether concept is useful for the understanding of physical phaenomena; and fourth, the hypothesis of an ether in apparently void spaces is useful for the future development of science. The paper also endeavours to show that no recent advance of science changed those conclusions and that no future development can change them.

This paper describes the four causes accepted by Aristotle, and then focus upon his concept of final causes, especially emphasizing its use in the study of living beings. The article discusses several difficulties in interpreting Aristotle’s teleology, such as its relation with the concept of a providential god, and the difficulty of understanding goals in processes that do not include intelligent agency. The Aristotelian ideas on final causes are highly complex, and they are widely different from those usually ascribed to the philosopher. RESUMO: Este artigo apresenta uma descrição dos quatro tipos de causas aceitas por Aristóteles, centralizando-se depois nas causas finais, focalizando principalmente seu uso no estudo dos seres vivos. Discute diversos problemas da interpretação da teleologia de Aristóteles, tal como sua relação com a ideia de um deus previdente e as dificuldades de compreensão de finalidades em processos que não envolvem agentes inteligentes. As ideias aristotélicas sobre as causas finais são altamente complexas, e muito diferentes das versões simplistas que costumam ser atribuídas ao filósofo.

Lamarck's evolutionary theory has been regarded as groundless speculation by both coeval naturalists and modern historians of science. Lamarck is usually regarded as belonging to the group of the " idéologues" – followers of Condillac, with a strong empiricist outlook. Indeed, Lamarck refers respectfully to Condillac, and in his methodological discourse presents himself as an empiricist. However, if one compares his evolutionary theory with the empiricist requirements, Lamarck's work should be dismissed as groundless – a mere metaphysical " système" – in the pejorative sense used by the followers of Condillac. There is, however, another way of looking at Lamarck's method. The analysis of his later works – specially Histoire naturelle des animaux sans vertèbres and Système analytique des connaissances positives de l'homme – shows that he did not follow an empiricist method. His point of departure is indeed metaphysical, but it is exactly the kind of metaphysics now accepted by the biological sciences: a strict physicalism, that requires that all natural phenomena be explained by natural laws. Following this requirement, Lamarck's method seems the best available solution of that time to the fundamental biological problems: the nature, origin and structure of living bodies. Lamarck's work was criticized as purely speculative and non-scientific because it was evaluated in the context of empiricism. He was not altogether clear about his method and maybe he did not realize that he was departing from the empiricist tradition. The reinterpretation of Lamarck's theory from the point of view of his non-empiricist physicalism allows a favorable evaluation of his work. RESUMO: A teoria evolucionista de Lamarck tem sido considerada como uma especulação sem fundamento, tanto por naturalistas de sua época quanto por historiadores atuais da ciência. Lamarck é usualmente considerado como pertencendo ao grupo do "idéologues" – seguidores de Condillac, com uma forte tendência empirista. De fato, Lamarck se refere com respeito a Condillac, e em seu discurso metodológico apresenta a si próprio como empirista. No entanto, se compararmos sua teoria evolucionista com as exigências empiristas, o trabalho de Lamarck deveria ser rejeitado como desprovido de fundamentos – um mero "système" metafísico – no sentido pejorativo utilizado pelos seguidores de Condillac. Há, no entanto, outro modo de considerar o método de Lamarck. A análise de seus últimos trabalhos – especialmente os livros Histoire naturelle des animaux sans vertèbres and Système analytique des connaissances positives de l'homme – mostra que ele não seguia um método empirista. Seu ponto de partida era na realidade metafísico, mas é exatamente o tipo de metafísica que é atualmente aceita pelas ciências biológicas: um fisicalismo estrito, que exige que todos os fenômenos naturais sejam explicados por leis naturais. Seguindo essa exigência, o método de Lamarck parece a melhor solução disponível naquela época para os fenômenos biológicos fundamentais: a natureza, a origem e a estrutura dos seres vivos. O trabalho de Lamarck foi criticado como puramente especulativo e não-científico porque foi avaliado no contexto do empirismo. Ele não foi totalmente claro sobre seu método, e talvez ele próprio não tivesse percebido que estava se afastando da tradição empirista. A reinterpretação da teoria de Lamarck sob o ponto de vista de seu fisicalismo não empirista permite uma avaliação positiva de seu trabalho.

There are several kinds of studies about science (metascientific): empirical studies (grounded upon historical, sociological and other factual data); formal studies (analytic studies, that is, grounded upon logical analysis, definitions, formal distinctions); and axiological studies (grounded on value analysis). Those approaches are epistemologically independent from each other, in the sense that from one of them it is impossible to draw conclusions pertaining to the others. Every normative proposal concerning science is essentially axiological, because it is associated to value judgments (what is valid or invalid in science), and it is impossible to justify norms from empirical or analytical studies. It is important, therefore, to avoid confounding those three approaches, or passing from one of them to another without due notice, because this would lead to epistemological error. In order to emphasize those distinctions, the paper proposes the names "science of science" to describe empirical studies, "scientific methodology" for axiological studies on science that are grounded on internal values, and "analytical epistemology" to refer to formal studies, that merely offer coherent alternative descriptions of science. RESUMO: Os estudos sobre o conhecimento científico (metacientíficos) podem ser de vários tipos: empíricos (baseados em dados históricos, sociológicos, etc.), formais (analíticos, ou seja, baseados em análise lógica, definições e distinções formais) e axiológicos (baseados em análise de valores). Essas três formas de abordagem são epistemologicamente independentes, no sentido de que uma delas não permite tirar conclusões sobre as outras. Toda proposta normativa sobre a ciência é essencialmente axiológica, por estar associada a juízos de valores sobre o que é válido ou não na ciência, e não se pode justificar normas a partir de estudos empíricos ou a partir de estudos analíticos. É importante, por isso, não confundir os três tipos de abordagem, nem tentar passar inconscientemente de uma para outra, pois isso levaria a falhas epistemológicas graves. Para enfatizar essas distinções, o artigo propõe os nomes "ciência da ciência" para os estudos de base empírica, "metodologia científica" para os estudos axiológicos sobre a ciência, baseados em valores internos, e "epistemologia analítica" para estudos formais, que estabeleçam meras alternativas coerentes para a descrição da ciência.