Author: Marcos Rodrigues da Silva, Professor-associado/Universidade Estadual de Londrina. Rodovia Celso Garcia Cid PR 445 km 380 – 86057-970 – Londrina – PR – Brazil.email@example.com
Research in science education have pointed out the importance of a discussion about the nature of science. One way to convey a more real nature of science teachers would adopt a philosophical attitude about the concepts that denote unobservable entities. In the case of concepts already abandoned by scientific theories – such as phlogiston – is common to present that were discarded because nothing represented empirically. However, at the time of using the concept of phlogiston, he formed part of a network that was theoretical and explanatory justified its adoption. This article takes the view that the adoption of philosophical positions towards scientific concepts must be supported by knowledge of the history of the concept.
Research in science education have pointed out the importance of a discussion of what is called ‘nature of science’. The term covers a wide range of topics: understanding the inner and outer workings of science (Scheid, Ferrari, Delizoicov, 2007, p.158); improvement of ideas of students and teachers (Oki, Moradillo, 2008, p.71); establishment and modification of epistemological conceptions of teachers (Beach, Gil-Perez, Vilches, 2007, p.147); scientific and technological literacy (Acevedo et al., 2005, p.4); understanding of the history of science as a relevant source for understanding the nature of science (Matthews, 1994, p.50-52); understanding of theoretical aspects of science, so that these aspects do understand your practice (Fourez, 2003, p.118); structuring of experiments and observations in broader conceptual schemes, or “paradigms of thought” (Lonsbury, Ellis, 2002, p.3). And these topics, we can infer is the concern with scientific training in the broad sense. So if you want the scientific training includes a scientific literacy teacher and student, and that, beyond the content itself, seize these other aspects that are linked to the content, which, so to speak, constitute somehow . In this article the discussion about the nature of science prioritize the role of history of science in education.
One of the main issues related to the problem of understanding the nature of science concerns the image of her that is conveyed by teachers. This image (reflected especially in textbooks) often has as elements the concepts that it (a) is fundamentally an experimental activity, (b) is progressive (if ever closer to the truth) and (c) is an activity-guided methodology (universally accepted) well defined. The whole problem is that historians, sociologists, psychologists and philosophers of science have insisted on reporting this image ‘not always’ reflects the actual practices of scientists, or even that our attempts to understand the actual practices of scientists produce results too modest to one can use the expression ‘actual practices’.
In this article I’ll stop in element (c) above: the methodological element of our popular image of science. This element receives an input epistemological another element that was not mentioned: fallibilism.1 Currently you can see that is already part of our common sense scientific conception that scientific theories can be replaced by theories that judge better than the previous ones. And as we proceed in this-substitution? By using a scientific method that allows us to clearly point out that a theory is superior to another. Now, one of the natural consequences of replacing a theory is that certain other entities, mechanisms and processes that formed the scientific ontology2 theory replaced disappear. Thus, Copernicus does not use the notion of epicycles Ptolemy, Galileo did not use the Aristotelian notion of natural place, Darwin does not adopt the conception of a divine plan; Lavoisier does not accept the existence of phlogiston etc.. Such substitutions would be legitimated by the use of a reliable method that would allow us to, ‘after the substitution has occurred’, say that our ancestors were mistaken considerably. In this conception, to be criticized in this article, men like Galileo and Lavoiser have shown us the ‘right way’ to be followed, involving the elimination of so-called unobservable entities’, ie, entities that have been postulated by theories (and were part its ontology) but which, upon removal of theories have also been eliminated.
But one could argue: if an error occurred in the past, maybe there in the future also.3 And if this argument is valid, who knows what is best to adopt a modest stance regarding the admission of new scientific entities.Perhaps today there are also unobservable, argue a teacher and philosophical historiographically instructed.4The picture is clear: one can argue for the existence of the entities that populate the universe of current theories, on the other hand one can argue that they may not exist. The game takes place these arguments in a forum specific philosophical: the debate realism / antirrealismo.
According to Michael Matthews (1994, p.163) would be useful for teachers and students realize that this debate is central to understanding the nature of science. This is because such teachers would be responding to her students the following question: scientific concepts are names of entities and real processes (ie, make up the ontology of a theory) or are just fictions (ie, only part of the mental constructs of theory)? Generally speaking, scientific realists respond that we can infer the existence of the entities named by concepts; antirrealistas now argue that we can not claim that scientific concepts denote processes independent of theories.5 In the specific case of the problem that will be examined in this article, we want to know if the science teacher adopts a realistic or antirrealista about the theories that teaches its students. Students are taught true theories or fictions and built the formal point of view? Students are taught about the real processes of nature or just fancy ways of dealing with nature? For Michael Matthews, understand the nature of science is a task which no educator could escape.6 So far everything seems very plausible, and a philosophical point of view, quite civilized. But would such as didactic interventions from what was established in the preceding paragraphs? Think from an imaginary example. Professor realistic, of course, emphasize that the transmission of hereditary information occurs by action of, among others, genes – which actually exist. Professor antirrealista say that such transmissions occur because of biological units (genes) that we do not know for sure whether or not there. The situation seems curious, because the teacher realistic then behave more or less like someone who says your tire fitter: arrange the tire of my car: the tire there, the car also! But Professor antirrealista would have to say: I do not know if there are the right tire and car, but just in case fix it the same way. Both seem to give the impression that philosophy is a luxury only rhetorical, an intellectual position that – with regard to science teaching – can maximum satisfy certain whims epistemological that perhaps someone may have. In this sense everything suggests that ‘from the point of view of science education’, there is not much sense in taking seriously the controversy realism / antirrealismo.
Michael Matthews seems to be quite aware of the risk of the discussion realism / antirrealismo flowing into the intellectual vacuum in the previous paragraph. So much so that he claims that “approach the subject from contrasts so limited would not appreciate the nuances of the story” (1994, p.174). The ‘limited contrast’, of course, would be the intransigence ontological genes exist (for realists) or no (for antirrealistas). This contrast prevents a better understanding of the ‘nuances of the story’. But what would these nuances? Matthews recalls the old opposition between empiricism (antirrealista) Mach and Einstein realism about the existence of the atom. It would be a mistake, says Matthews (1994, p.174), describing the opposition as simply, as the real story of the episode certainly deserves more than ontological statements (“the atom exists”, “the atom does not exist” .)
This article aims to explore the field of discussion realism / antirrealismo in science education from the historiographical orientation of Matthews. Try to show that this discussion is not only a way to establish ontological verdicts. It can also be an extremely useful tool, in conjunction with the history of science, ‘understand’ something about the nature of science. This is because the history of science reveals that in several episodes, not always the most important was the inference of the existence of entities and processes now widely accepted by the scientific community. My strategy will be to show, by means of an episode in the history of science – the construction of the concept of oxygen – which is not always the discussion about the existence of entities and processes is the most important discussion. In so doing, ie, by not putting in the foreground the ontological discussion at hand, scientists seem to give the impression that whether an entity or process is not exactly the most important issue from the point of view of theory building scientific explanatory. In reviewing this episode we see that, at least in it, rather than whether certain entities and processes exist (or not), which told the scientists involved in it was the construction of hypotheses that effectively explain phenomena that should be explained. Thus, presenting the problem of whether the entities and processes described by the best scientific theories indeed exist in a form of ‘yes or no’ does not appear ‘in the light of this episode,’ do justice to the actual procedures adopted and used by scientists. And with that, the requirement that a science teacher adopt a realistic stance or antirrealista sounds like an extremely complex requirement, if that teacher is not aware of the content of the story that he teaches. That is, there is the case of demanding then the teacher has only one philosophical stance on the issue, but also knowledge of history (what for which he will take a philosophical position). Therefore understanding the nature of science, in this case, is to understand a series of interrelated aspects to the ontological question – aspects which I hope to show, are equally or more important than the actual ontological question.
This article presents, in the first section, the importance of the discussion about the nature of science. Then – through the outline of a case study of the history of chemistry – show that one aspect of the discussion about the nature of science – the question of the existence of scientific entities – can be addressed in a more profitable with the use of history of science . In the third section of the paper I argue in favor of emphasis on explaining the science; aspects which seem most relevant to an understanding of the nature of science than the ontological aspects. Finally, in conclusion, I argue that discuss the problem of the nature of science is both have limitations that seem inherent in the form of construction of scientific objects.
This article is the result of research in philosophy of science from historiographical approaches, research which falls also in discussions about science education.
One of the strongest claims of theorists of science education regard to obtaining an insight into the ‘nature of science’. The expression ‘nature of science’ undeniably covers a wide range of meanings, and certainly would go beyond purely scientific aspects of the production and justification of science, since it should also refer to social science. However, for this article, we will use the term as denoting the internal aspects of science.7
From the theoretical point of view, what kind of knowledge would be drawn from an investigation into the nature of science? It could be argued that it is a metacognition, that is, something that hangs above the own knowledge produced by science. For Acevedo et al. (2005, p.2) obtaining their metacognition revealed an ambitious goal. Pertinently, the authors call for the teaching of science some answers to certain questions, one of which is: “what kind of science we mean [the nature of science [?” (P.7). For them, science is a polysemic concept, since it refers to various forms of activities, and thus can not identify “academic science” (p.7) with “macrociência” (p.7), which was an activity that includes the Army and industry; authors also point out that the debates about the nature of science in general focus on academic science (p.6).
The general methodology of work points to an aspect that we share with Acevedo et al. (2005). As the authors problematize obtaining a conception of the nature of science restricted to ‘academic science’, this article discusses the view that the conceptions about the nature of science may derive from a position opposite the philosophical debate realism / antirrealismo. This is because the result of such a pronouncement can provide an image of science that ignores the complexities of the history of the concept (or theory) to be defending as ‘real’ (realist position) or as ‘fiction’ (position antirrealista). And an image of science that does not reflect the complexity of scientific (academic) may undoubtedly miss some important aspects of building certain concepts and theories that are now established.
Before seeking to develop this point (development that will actually be done only in the next section) would like to explore further the complexity of scientific activity, since, by assuming its existence, more easily realize that philosophical attitudes about acceptance of scientific theories and entities ‘may’ be sterile when dissociated conceptions about how emerges a theory or concept. Likewise, scientists attribute to the adoption of certain research methodologies and certain attitudes axiological order to explain the emergence of the theory proposed by them without at the same time, take into consideration the circumstances (in the case of our article, scientific circumstances ) that led her to propose conceptual scheme ‘may’ be a way to truncate a conception of the nature of science that otherwise would prove a bit richer and therefore more useful for the assessment of science. So it seems important to hold some meaning in the complexity previously mentioned.
The complexity identified seems to result from the complexity of the science itself, especially with regard to the mode of construction of scientific knowledge. Why is it so difficult to say that a scientist proceeded inductively or deductively? Why is it so complex to say the first scientist built a hypothesis and then tested or auditioned first and then built a theory? These issues are complex, given that we can not always reconstruct historiographically such steps in an orderly way, since science, like any human endeavor is not always constructed so commanded.
According to Singer (1989, p.159) notes lab scientists reveal clues that there are discrepancies between what scientists actually did and what they reported in their publications; yet for this author (p.160), this count as evidence that personal notes and literary publications are vehicles that have distinct forms, as well as their goals are distinct and conventions that govern them. As for Lewontin (1998, p.108), scientific journals standardized scientific publications to require certain sequence of items (introduction, methods and materials, discussion, results, conclusion and summary). To him, the whole importance lies in its ‘results’ that reveal ‘that speaks for itself’, ie, the empirical results, which confirm the theory.
One way of ordering the chaos is to establish a methodology of analysis for a certain problem. Say we are interested – as in the case of this article – to understand the dynamics of acceptance of scientific entities. In this case we can think as follows: certain periods of science reveal disputes about the existence of certain entities, such periods are followed by another period in which disputes no longer occur. The question is: why disputes occur no more? One answer (which will not be of this article, as will be seen below) would be: the dispute is not because one of the contenders emerged victorious, with his victory the expression of truth about nature. Thus, phlogiston was declared nonexistent because in fact did not exist. The problem with this methodological approach is that it makes such disputes in a discussion as to whether or not there is a cat on the roof of the house, I hear noises on the roof, climb to the roof and can not find a cat, but a loose tile, can then declare that there is no cat on the roof. But science proceeds in this way? Probably not. And then someone could reply, but then how comes? Here is the point. It would be reasonable to try to answer satisfactorily the last question? As we? Indeed, it is this gigantic task that is being carried out by philosophers, sociologists, historians, psychologists etc..: Understanding the dynamics and structure of scientific knowledge production. This understanding, in turn, reveals considerable difficulties. These difficulties arise primarily according to the peculiarities of each scientific episode. So, how to apply wide-ranging philosophical methodologies to assess episodes that are private in nature (Feyerbend, 1996, p.96-99)?
A clear example of these difficulties can be encountered when trying to understand the history of science using the schema cyclic Thomas Kuhn (1970). As we know, Kuhn divides the history of a scientific discipline in four basic stages: (a) a stage in which there is no consensus on the fundamentals of a science (pre-normal science), (b) a stage in which the scientific community is consistent with respect to key aspects of a science (normal science), (c) a period in which science is well established in (b) is under suspicion of some members of the scientific community (crisis), (d) scientific revolution: given the mistrust, the foundations of (b) are shaken and there is a new period of normality from new fundamentals and scientific problems. While scheme, the proposed Kuhn may prove a guide to interesting historiographical research, but is that all science can fit point to point in this scheme? Furthermore, the schema is also summarized. In this sense, it is evident that a methodology of historical analysis has limitations in its application. The same, the principle applies to any scheme. The limitation is also, in turn, an indication of the wealth of science. And this wealth dynamics of science shows that it is not a simple task to introduce, for example, the ontological commitments of scientists, as well as the role that such commitments occupy in their investigations, at least not if such commitments are evaluated outside its original context. So if it is true that one of the important aspects of nature of science is the ontological dimension (in fact scientists are committed to the existence of entities), it is no less true that this dimension is located in a wider network. And with that, the record that the ontological dimension is a fundamental aspect of the nature of science could not be done without simultaneously remember that this aspect is not isolated nature of science.
What we are suggesting is to answer yes or no to the question “such an entity exist?” is insufficient to adequately understand the ontological aspect of the discussion about the nature of science. And is insufficient considering that, at least for the episode that will be examined in this article, not always the scientists are ‘primarily’ interested in ontological questions. Sometimes this interest ‘may’ be secondary. For the episode of the discovery of oxygen, there is strong evidence that historiographical Lavoisier clearly avoided discussing the problem of non-existence of phlogiston, as discussed below. Instead, he sought to systematically build a viable alternative to the theory of phlogiston – alternative, of course, would also ultimately lead to new chemical does not work with phlogiston.
Thus the return to the history of science can be an expedient very useful for understanding the nature of science from the viewpoint of the cognitive significance of theories, but what do we find in this return? It is difficult to say that we will not find scientists obeying the rules of introduction and admission of scientific concepts, but it is also very difficult to find them with the clarity that if you like. However, from the point of view of science education, it is appropriate (to say the least) show the difficulties encountered by scientists to introduce new concepts (or reformulate old). More than that: the point of view of understanding the nature of science is important that teachers are clear that such difficulties scientists emerged in view of the problems arising from the internal structuring of the conceptual network as a whole. Thus, a conception of the nature of science could emerge from this discussion, with handsome dividends teachers.
The history of chemistry, in the period before Lavoisier (around the late sixteenth and early seventeenth century), the proposal and maintain records of the phlogiston theory. According to this theory, among the principles governing changes of state of the bodies found itself the principle of flammability, phlogiston. When was the burning body changed state because releasing phlogiston. The ash from burning were nothing more than the production of a chemical change in which the originating body (a piece of wood, for example) has released its share of phlogiston and, thus, became gray. A similar process occurred with the rusting (oxidation): rust was the result of the release, by the metal, its phlogiston, albeit slower. According to the chief defender of the phlogiston theory, Georg Stahl, combustion and rusting obey the same chemical processes, albeit at different speeds. In short: the explanation for both phenomena was found on the same principles.
The term phlogiston theory was intended by its users as denotador a substance that, at first, was lacking in referentiality. Where was the phlogiston? The phlogiston was not gray and rust, but a principle that became gray and rust. In burning, it was assumed that this principle was evading flammable (Leicester, 1971, p.120). Well, if it were true that phlogiston was being released from burning and rusting, then it should be possible to say something about its properties.
An extremely interesting historiographical discussion proposed here is that fool who thought that the discussion revolved only around the properties of phlogiston.
Here we enter an interesting point for debate realism / antirrealismo. One thing is to say that ‘theory’ phlogiston ‘explain’ phenomena, and another is to say that a central term of this theory – phlogiston – ‘has empirical reference’, it is important to remember that the history of science, a work conjunction with the philosophy of science, reveals the existence of a certain tolerance of the scientific community with postulated entities (Kuhn, 1970, p.127-128). In the case of phlogiston, it was contained in a theory which, in his time, explained so successful why certain phenomena behaved the way they behaved (Leicester, 1971, p.123, Smith, 1981, p.113) . In a philosophical model that privileges the problem of scientific explanation there is no reason to be offended – at least preliminarily – the question of the absence of empirical reference to the alleged entity phlogiston. Tolerance, however, is not unlimited or unconditional. Once established a theory, it follows a work of improvement and sophistication of the theoretical apparatus originally proposed. Presupposed the phlogiston theory as an explanation, should succeed work to identify the effects – and ‘only’ effects – its supposed existence as a principle (Leicester, 1971, p.123). Thus, one of the important issues of that time concerned the role of air in combustion. It would be just the vehicle propagation phlogiston or would play a role in chemical combustion?
One of the scientists who held a prominent role in the discovery of the chemical on the gas and the air was Joseph Priestley. During its investigations, it came to designing a ‘desflogistizado air’: combustion would be a quick process because releasing an equally rapid phlogiston. The air present in the combustion air was a pure air that contained no more inflammable principle of bodies, an air containing no more phlogiston, already released in combustion. However, what would be the point of view of the formation of a new concept, the ‘air desflogistizado’? For sure it was a novelty, however, its scope was not broad enough to exclude (not desired by Priestley) the concept of phlogiston chemistry. Indeed, state that air does not contain flogisto is still moving within an area containing the theoretical concept of flogisto.9 And in the empirical domain, an air desflogistizado is an air that does not contain a substance that is somewhere else. If we follow the guidance of Priestley, phlogiston is still a relevant concept for understanding certain chemical processes. Here, in fact, what happened was that Priestley discovered oxygen – almost simultaneously with the discovery of this element by Carl Scheele – and called coherently of ‘air desflogistizado’. This season marks the end of the theory of flo-gisto and records the emergence of Lavoisier in chemistry. The French chemist opposed the phlogiston theory from the beginning of their work. It is interesting to note, briefly, as Lavoisier built his opposition to this theory, especially with respect to its theoretical caution.10
According to Paul Thagard, one must take into account that the attack of the phlogiston Lavoisier should be understood only as a part of its production, which resulted in the creation and dissemination of a new system of chemistry. Thus, Thagard examines, from the works of several historians, movements Lavoisier since his initial experiments until its proposed explanation of the phenomena of combustion and oxidation. Initially the opposition of Lavoisier’s theory of phlogiston is marked by a tendency experimental, this time culminating in 1772, with a note addressed to the French Academy in which he reported his experiments weighing of phosphorus and sulfur after combustion and emphasizes they were heavier after the process (Leicester, 1971, p.140-141, Partington, 1937, p.125). Also points to an explanation for the process: the presence of air. The air was pure agent who joined the metal making them heavier. Here already, so surreptitious, a critique of the concept of phlogiston: if the body became heavier after firing, so he has not lost phlogiston. However, no experimental evidence corresponds to a theoretical formulation also more robust concerning the properties of air and the absence of this theory Lavoisier leads to doubt about the potential explanations for their chemical processes in question, which leads Thagard (2007, p. 276) stated that
he is still not very confident that you have a strong alternative to the phlogiston theory of Stahl, it states that the current state of knowledge on the calcination and reduction does not allow us to decide between his interpretation and phlogiston, and that opinion Stahl may be compatible with your. In 1776, Lavoisier admits in correspondence, which often have more confidence in the ideas of the eminent English theoretical phlogiston – Joseph Priestley – than in their own ideas.
A second phase takes place around 1777, when Lavoisier address the problem the first time, namely, the problem of identifying more precisely the properties of air involved in combustion. Lavoisier presents the idea that the air is atmospheric air ingredient, and that air combines with the metals is a mixture of two components (Leicester, 1971, p.142). The problem is that this development is still inside the structure phlogiston, as Priestley also is one of the scientists who are working on research on the air. Priestley also reached the conception of a pure air, and the air in the structure phlogiston, was not exactly an air phlogiston. At that time, 1778, Lavoisier publishes another article reporting their research. In this statement he shows some impatience with the failure of some scientists to isolate phlogiston and suggests that, according to Thagard (2007, p.277), “even though they may abandon the phlogiston theory,” the hypothesis that the combination of the air with the metals is less artificial and contradictory than the phlogiston theory. Thus, it is only in this second moment Lavoisier admits that the phlogiston theory to be inferior to another alternative. The third and decisive moment occurs around 1783. At this time Lavoisier begins to use the term ‘oxygen’. Additionally first suggests that “since the theory of oxygen is higher than flogisto theory” (Thagard, 2007, p.278-280), then it is unlikely that there flogisto. Therefore, according to Thagard, replace the phlogiston theory was simultaneously proposing a new alternative explanatory. But note that we are not talking about phlogiston itself, but the theory that the houses.11
Realize chaining these three moments can be enlightening to understand the debate realism / antirrealismo and their implications for teaching. You can see that the episode suggests much the occurrence of a struggle for explanations of the phenomena of the occurrence of ontological disputes. Lavoisier avoids the non-existence of phlogiston, and even when it is suggested, has a view to explaining the superiority rival the phlogiston theory (Thagard, 2007, p.278). Thus, the history of chemistry reveals in fact a dispute – but the nature of this dispute?Again the story of the episode comes to our aid. One of the strengths of the system Lavoisier did not occur in the field trial itself, because there was no question that metals gained weight during combustion – only in the period in which the phlogiston theory of fenecia fact is that questioning was experimental, with the statement that phlogiston had negative weight (Thagard, 1978, p.78). Questioned the importance of the concept of weight to explain what should be explained, which is a strategy fully justified the methodological point of view (Laudan, 1977, p.84). Ie, it was possible that the phlogiston theorists would lead to dispute not for testing ground, but for the methodological domain.
What is important to note is that the introduction of the concept of oxygen by Lavoisier was not the introduction of a single entity, but rather that entity had to be assimilated within a ‘new’ theoretical network (Kuhn, 1970). Even because the concept of oxygen, by itself, could be interpreted – as indeed it was by Priestley – as a concept of phlogiston theory because the evidence could be assimilated by this theory. The truth is that Lavoisier needed theoretical principles robust enough to constitute a theoretical manner alternative to the theory of phlogiston. He needed to weave a theoretical network to rival the phlogiston theory and will impose methodological standards and explanatory unattainable.12 Perhaps this was more decisive for the success of Lavoisier than their experimental and methodological achievements, which were actually playing the experimental work of other chemicals (Partington, 1937, p.122). Even his demand for a quantitative approach in chemistry was derived from other chemicals, such as Robert Boyle and Joseph Black (Partington, 1937, p.124), and had already been adopted by Cavendish (Ladyman, 2002, p.7). Lavoisier built a new explanatory theory, can be considered a new ‘form’ of explanation, because the new concepts introduced by him not only replaced the old (like phlogiston), but also established new connections between all the theoretical network would be structured to provide explanation of calcification and combustion (Thagard, 2007, p.184). To get just one example: the theory of phlogiston, phlogiston itself and oxides were components of metals, whereas the theory of Lavoisier, oxygen and metal oxides formed, it is realized that, in addition to the elimination of some concepts (like phlogiston), there was also a new mount for the structure. In other words, it was not the case to say that oxygen and oxides were components of metals, which would mean simple replacement of phlogiston by oxygen.
It would seem a mistake to think that with the abandonment of the phlogiston theory, we get rid of a burden metaphysics in chemistry. Naturally, given the implementation of the new program Laovisier is convenient to say that the concept of phlogiston represented nothing ‘empirically’, but he had, in his time, a scientific meaning, as was contained in a theory which, by the standards of the time was explanatory. Certainly, proponents of the phlogiston theory did not think his central substance as something metaphysical, and in their laboratories, understood that the flames from burning materials were manifestations of the action of a substance that had the property ‘being flammable’ – phlogiston . And if it was possible to criticize the hypothesis that the flames were coming undone because of phlogiston, that ‘no’ is given by the fact that someone had said, “this is not because of the action of phlogiston, but for another reason . “ In fact, there was only a replacement game ontological (or phlogiston or other substance), but a change Explanatory combustion is explained without reference to phlogiston, but with reference to other very different from those described by the theory of phlogiston. But the most important point to be noted is that the whole question of the oxygen and phlogiston is located in the center of a scientific revolution: Lavoisier is proposing a new conceptual framework. In this new scheme presents an equally new chemical nomenclature, it emphasizes the search for explanations that are quantitative in nature etc. There is therefore only a matter of knowing something about phlogiston or oxygen.
It has been said by many that science is a human construct, and there is no reason to deny that consensus. As humans, we tend to want explanations for the phenomena, and as humans, we provide explanations (Psillos, 2002, p.1). For example, we say that the cause of the tsunami is the agitation of tectonic plates. We also say that the cause of falling bodies is gravity and that the cause of combustion is the action of oxygen. The problem is that all these examples are presented by means of linguistic forms inadequate to express what seem to occur in science.13 It is not exactly correct to say that “the cause of falling bodies is gravity.” It would be perhaps more accurate to say that there is a mechanical theory – consists of laws, concepts and principles, including gravity – which explains, among other things, the falling bodies. The acceptance of major scientific theories successful (those that are taught in schools and included in textbooks) occurs mainly for the reason that they explain series of phenomena, and not isolated phenomena. In any case the point is not to correct our form of expression, but rather the realization that, with regard to the scientific explanation, scientific theories occupy a key role. And here is the problem, as would surely be deceived if we were told the story of the chemical revolution as ‘succession’ of the discoveries of Lavoisier (and others) in pursuit of solving certain problems. As we have seen, very early Lavoisier discovers that metals gain weight during combustion. But everything suggests that the explanation of this finding was only part of an immense work that should be done. Lavoisier did not have to just ‘show’ the extra weight, but rather should ‘explain it’. As the explanation is a function not of the experiments, but a theory, it should then build your. And, as a (large) theory is not only the explanation of a phenomenon, others should be explained – which gradually complicates the process as a whole. In plain terms: Lavoisier not only has to explain combustion.
The process is further complicated when we consider other important dynamics of the explanation. In the case of Lavoisier, he not only provided some explanations for the phenomena, but instead, he presented a ‘new way’ of explanation – which, in his case meant building a new chemical. This clearly reveals the emergence of a new form of scientific explanation is a process far more complex than simply show that mercury is heavier after heating. By proposing a new way of explanation, Lavoisier not only need to show the results of warming, but also ‘convince’ his interlocutors that a methodology mathematized is a good way to understand, among other things, the familiar combustion. It follows a certain image of science. We no longer ‘just’ the scientist in his laboratory weighing the lead. We also have the theoretical (you need to build networks explanatory) and rhetoric (which must convince their peers of relevance to weigh the elements). This image of science presents us with the construction of scientific knowledge in such a way that answers ‘yes’ or ‘no’ begin to lose some of its strength, and mainly, this image shows us the difficulties that faced the great scientists and face to propose new ways of dialoguing with reality. We believe that the perception of these difficulties, by teachers, could hardly fail to be considered as a way to understand something about the nature of science.
And the interesting thing is that in presenting such difficulties, the chemistry teacher would be providing an outstanding historical example of how science really works. Of course, this new framework, Lavoisier is not the experimenter that the old rule of chemistry and troublesome metaphysical baggage exemplarily represented by phlogiston. In the new framework Lavoisier doubts, hesitates, waits for the moment he thinks right to disseminate their ideas etc.. Likewise, its adherents are not men who decree that oxygen exists and that phlogiston does not exist. Scientists are before they see the theories of Lavoisier an opportunity to establish a new research agenda for chemistry, this book who expressed the desire for a new form of scientific explanation for chemical processes. In the new plot, phlogiston is no longer a character desirable. But note: this is not to say that phlogiston does not exist.14 What happened was that since Lavoisier, efforts have focused on showing that phlogiston did not exist, but in developing new chemistry proposed by Lavoisier. What is important to disclose that is part of the nature of science to elect certain problems and give up others. Course a thorough historiography ought to evince ‘why’ certain problems are elected. But this leads to discussions beyond the scope of this article, especially considering that the admission of scientific problems has a dynamic that is not only scientific but also social. When Lavoisier’s chemistry takes the scene very quickly disappear references to phlogiston, while not having been declared nonexistent. Thus, it is no longer an issue whether the phlogiston has certain properties, not the fact that phlogiston ‘no more’, but because the scientific questions had changed.
Douglas Allchin produced a case study in a science lesson by using the concept of phlogiston. At the end of this intervention Allchin (1997, p.486) reports that, after students have used the concept of phlogiston, they would lower propensity to consider that past ideas were wrong and the current were self-evident. Interestingly Allchin’s article draws attention to the construction of understanding of a concept that is part of the past history, but without making references to ontological problems. Instead, it proposes an understanding of the concept in its context of production.
Understanding the nature of science is also to understand the dynamics of the production of certain scientific problems, since, in such a dynamic, just by assuming the existence (albeit alleged) of certain entities. But, if they are assumed by virtue of the necessity of theories, then it must be admitted that need.
It may be tempting, the scientific educator, joining a pedagogical proposal indicating the importance of the debate realism / antirrealismo to one or more topics of their discipline. But the presentation of this debate without mention of a sophisticated history of the subject can end up distorting the history of the subject, and, of course, to provide an image of science committal to a proper understanding of the nature of science.
In this case, it would be tempting to present Lavoisier as the man who (a) did not believe in the existence of phlogiston and, moreover, (b) showed their absence. We have seen that there are records historiographical who deny (b) and show that (a) seems to be irrelevant. And it would be tempting? Because, presented thus Lavoisier settles our commonsense historiographical; settles to our popular image of science, especially to its progressive nature. Also can make things worse present discussion emphasizing the experiential aspect of research and Lavoisier later contrasted with that aspect of the difficulties in discovering the chemical properties of phlogiston. The picture of contrasts that there would emerge more or less as follows: first we Lavoisier with his theories testable by experiment, on the other had phlogiston theorists who defended theses not amenable to empirical confirmation. This framework is both historically and philosophically indefensible misleading.
From the historical point of view is misleading because (a) can not deduce the impossibility of direct experimentation of an item of chemical (in this case, phlogiston) the conclusion that all the phlogiston theory was not testable empirical; ( b) one can not evade the historical information that, despite the problems with the referentiality of the concept of phlogiston, the tradition of research in chemistry before Lavoisier produced a considerable amount of empirical results, and (c) can not forget that although Lavoisier have in fact proposed a new form of dialogue with nature, many empirical results (eg research on the nature of the air) of the conceptual structure of phlogiston were important for Lavoisier himself. So one thing is registering the problems of referentiality one (though apparently central15 ) concept of a theory, quite another, it is noted that the theory as a whole had problems referentiality. From the philosophical point of view is unacceptable because there is no philosophical theory about science that requires that all concepts of a scientific theory have empirical reference.
Accordingly, tell a story from the perspective of the ‘winner’, although almost unavoidable, definitely always problematic. In the case of the story which we are dealing, the ‘loser’ placed its bets on unobservable phlogiston. What about stories in which the ‘winner’ bet on unobservable natural selection, double-stranded DNA, gravitational force etc..? Is it really the ‘loser’ unobservable lost because its not there, and the ‘winner’ won because their unobservable existed? This is a response to this article has endeavored to show how problematic. Another answer is that the ‘winners’ won not because they were happy to provide the references of all its concepts, but because they built networks that satisfy certain theoretical explanatory scientific demands considered important.16 If this response is accepted, it also emerges a picture of science that could be presented by teachers in their courses.
In the end, perhaps the most presumptuous philosophical solemnly affirm that electrons, leptons and genes do not exist, but it certainly is a philosophical contribution constitute investigate how our beliefs in the existence of these entities and scientific processes as complex. Complexity that is passed on to the moment of his historiographical reconstruction.
Faced with this complexity, how to behave chemistry professor who decide to incorporate into your program for reflection on the nature of science from the realism debate / antirrealismo? A historian devoted a lifetime to clarify one or two episodes scientific, a philosopher devoted a lifetime to structure the debate realism / antirrealismo, as in one or two classes, synthesize what is relevant historiographically an episode and discuss it with historical-philosophical property?
One suggestion would accommodate the episode chosen the traditional framework: show overcoming a theory by another. This suggestion is interesting in that it was not required of teachers a training historiographical greater. Another alternative would be for teachers to present students with the difficulties that great scientists – as Lavoisier – had to overcome in order to enforce their ideas. This overcoming, at least in the specific case of Lavoisier, was not simply the overcoming of the experimenter, but also of theoretical, rhetorical, scientist anyway. When viewing these difficulties, we would be facing a new image of science that point to the inevitable complexity of scientific construction. This is in full agreement with the proposed Matthews (1994 p.5), for whom science is important in the formation of the student’s knowledge also because of their failures. Narrating the failures (or difficulty) of science is, in a way, present it in a more rich and real. Thus, narrating the difficulties in the assimilation of Lavoisier’s oxygen concept is to present an image of science that to some extent reflects what is actually science.
Now, it could be objected that the alternative above is overly simplistic. What kind of historical knowledge the student would get from an exhibition of the difficulties faced by Lavoisier? Surely, it must be admitted, the student would have before him a few historical information. On the other hand, he was faced with what might be called ‘workup historiography’, before a way he can, if you want to understand the history of a scientific subject, enter so qualified the story itself.
Finally, we believe that the second alternative is not ideal. In fact, the ideal would be that science teachers possess a training historiographical and philosophical enough to narrate the story with the authority of the main episodes of his scientific discipline. It would also be the ideal curriculum, reserved space for the history and philosophy of science in the scientific disciplines, but may not be amiss to think in more modest alternatives.
The principle is not possible to know what would have happened if the chemistry the phlogiston theory had not been replaced by the oxygen theory, but history shows replacement and hence the replacement must be understood. One way to understand it is given within the debate on realism / antirrealismo, specifically in the field of ontological debate: a debate between Lavoisier and his rivals was about the ‘existence’ of certain processes and entities. But, as we have seen, the story of this episode can receive another interpretation: the discussion between Lavoisier and his rivals was about the best explanation for certain phenomena.
Now, if what has been plausibly argued, then the adoption of a philosophical attitude about the existence of scientific entities is nothing exclusively by discussions of ontological nature. Of course not denied here that whether an entity exists or not is an important discussion, however, such a discussion can not be located exclusively in the field of ontology. The explanatory dimension must also be taken into consideration.
On the other hand, a wider field, taking into account the explanatory aspect of science is to understand how complex it is and how we should be humble in our attempts to understand it. Science should not be considered fallible only by the fact that new discoveries are made, but because, when it appears, the novelty is not absolute. She is no longer absolute in origin, and not just because other novelty inevitably appear. That is the nature of science.
1 I will not dwell here on a presentation of fallibilism, generally attributed to the philosopher Karl Popper, in view of the more general aspects of his philosophical position is known to all who are dedicated to the issues of this article. I suggest, however, the classic scientif The logic of discovery (Popper, 1959), for a presentation today used his philosophy.
2 In other words, entities that theories assume to exist. Ontology thus relates to know that theories must assume to exist.
3 This argument is known as the argument of the ‘pessimistic induction’ and was made famous by Laudan (1981).
4 is a controversial issue of naming the ‘unobservable’ entities that are currently part of the scientific heritage, such as gene and electron. In general it is desired to preach if an entity as ‘unobservable’, that such entity does not submit directly to the senses, requiring sophisticated scientific instruments to their perception. A current controversy that exemplifies strikingly the situation is the concept of the gene. However, from the perspective of this article, if you want such controversies ontological not provide adequate understanding of how to use of such entities.
5 This form of presentation of the debate is schematic and serves the purposes of this article. For references about sophisticated forms of presentation of the controversy, see Lipton (1991), Psillos (1999), Boyd (1984) and Van Fraassen (1980).
6 will not be presented here in detail the proposed Matthews.
7 We recognize the limitation of this approach internalist, since science is an activity highly determined by factors external to its own dynamics, such as social factors. However here is a methodological choice made by internalist approach, which should in future be complemented by a more comprehensive approach to understanding the discussion of the nature of science.
8 This section is not intended to provide a story, even synthesized the episode. What it is intended simply leaving the results of some historians, discuss certain philosophical developments possible in certain moments of the revolution in chemistry. Historians mentioned are excellent sources for those who wish to understand the history of the period: Leicester (1971), Partington (1937), Kim (2008) and Thagard (2007).
9 On this point suggest the reading of Quine (1980, p.217).
10 Here we make an overview of reconstructive Thagard (2007), whose article also refers to important historical sources about the episode, which will not be mentioned here. For discussions of the author about other episodes in the history of science, see Thagard (1992).
11 As for Kim (2008), phlogiston became the target of a campaign rhetoric Lavoisier least for problems concerning the stability of the reference to the fact that he did not fit in the new system quantitative chemical that Lavoisier was proposing. According to Kim, phlogiston was not assimilated into the new chemistry of Lavoisier not because it was not real, because for the French chemist phlogiston was as ‘real’ as any other chemical. What happened was that the epistemological shift in the way research chemical was associated with an ontological change. Kim Thagard rejects the conception that there was a dispute between two explanatory theories, for him, not phlogiston provided an explanatory framework, but it was just a body chemistry.However, for the point of this article, it suffices to show the interpretation of Kim as a support of the idea that phlogiston was not abandoned by ontological issues. However, according to Allchin (1997, p.487) the concept of phlogiston in its context and in its scope, was reliable and guaranteed.
12 Not just a theoretical network, but also a form of social support (ie, within the scientific community of which it was part) for their research. The conceptual clarification of this social structure, however, escapes the purposes of this article.
13 One of the philosophers who draws attention to the misuse of scientific expressions is George Berkeley. In his De motu , 1720 (version in Portuguese, Berkeley, 2006), he warned about the inappropriate use of certain expressions. Another philosopher who discusses this point is Thomas Kuhn (1970).
14 On this point it is essential reading Quine (1980). To him, the issues of empirical reference of scientific concepts should be treated from a scan of ‘need’ a concept for a scientific theory. As we have seen, phlogiston was not needed in the new chemistry.
15 On the question whether or not phlogiston was a central concept of chemistry before Lavoisier, see Kim (2008).
16 A philosopher who worked with this issue, antirrealista perspective, was the aforementioned George Berkeley (2006). For him, Newton’s mechanics was successful, and this success explained why the scientific concepts used by Newton were established. But the success of Newtonian mechanics does not follow that these concepts represent empirical objects well defined.