Feyerabend, P. Feigl and G. Maxwell Univ. Butts and J. Davis , Univ. Radner and S. Winokur , Vol. Fine, A. Hesse, M. Kaufmann, W. Anchor Books, Doubleday, New York. Koertge, N. VIII ed. Buck and R. Cohen , Reidel, Dordrecht, pp.
A law is a description of an observed phenomenon in the natural world that hold true every time it is tested. It doesn't explain why something is true; it just states that it is true. A theory, on the other hand, explains observations that are gathered during the scientific process. So, while law and theory are part of the scientific process, they are two very different aspects, according to the National Science Teachers Association. A good example of the difference between a theory and a law is the case of Gregor Mendel.
In his research, Mendel discovered that two separate genetic traits would appear independently of each other in different offspring. It wasn't until a century later that scientists discovered DNA and chromosomes — the biochemical explanation of Mendel's laws," said Peter Coppinger, an associate professor of biology and biomedical engineering at the Rose-Hulman Institute of Technology. They have been thoroughly tested , are supported by multiple lines of evidence , and have proved useful in generating explanations and opening up new areas for research.
However, science is always a work in progress, and even theories change. We'll look at some over-arching theories in physics as examples: Classical mechanics In the s, building on the ideas of others, Isaac Newton constructed a theory sometimes called classical mechanics or Newtonian mechanics that, with a simple set of mathematical equations, could explain the movement of objects both in space and on Earth. The theory was powerful, useful, and has proven itself time and time again in studies; yet it wasn't perfect … Special relativity Classical mechanics was one-upped by Albert Einstein's theory of special relativity.
In contrast to the assumptions of classical mechanics, special relativity postulated that as one's frame of reference i. Special relativity was preferred because it explained more phenomena: it accounted for what was known about the movement of large objects from baseballs to planets and helped explain new observations relating to electricity and magnetism. General relativity Even special relativity was superseded by another theory. General relativity helped explain everything that special relativity did, as well as our observations of gravitational forces.
Our next theory … General relativity has been enormously successful and has generated unique expectations that were later borne out in observations, but it too seems up for a change. Foucault described his project as archaeology of the history of human thought and its conditions. Hence, in his analysis of the development of the human sciences from the Renaissance to the present, Foucault described various so-called epistemes that determined the conditions for all knowledge of their time, and he argued that the transition from one episteme to the next happens as a break that entails radical changes in the conception of knowledge.
For a detailed account of the work of Bachelard, Canguilhem and Foucalt, see Gutting One of the key contributions that provoked interest in scientific change among philosophers of science was Thomas S. History was expected to do more than just chronicle the successive increments of, or impediments to, our progress towards the present.
Instead, historians and philosophers should focus on the historical integrity of science at a particular time in its development, and should analyze science as it developed.
Instead of describing a cumulative, teleological development toward the present, history of science should see science as developing from a given point in history. Kuhn expected a new image of science would emerge from this diachronic historiography. In the rest of Structure he used historical examples to question the view of science as a cumulative development in which scientists gradually add new pieces to the ever-growing aggregate of scientific knowledge, and instead he described how science develops through successive periods of tradition-preserving normal science and tradition-shattering revolutions.
The predominant phase is normal science which, while progressing successfully in its aims, inherently generates what Kuhn calls anomalies. In brief, anomalies lead to crisis and extraordinary science, followed by revolution, and finally a new phase of normal science.
Normal science is characterized by a consensus which exists throughout the scientific community as to a the concepts used in communication among scientists, b the problems which can meaningfully be formulated as relevant research problems, and c a set of exemplary problem solutions that serve as models in solving new problems. In normal science, scientists draw on the tools provided by the disciplinary matrix, and they expect the solutions of new problems to be in consonance with the descriptions and solutions of the problems that they have previously examined.
But sometimes these expectations are violated. Problems may turn out not to be solvable in an acceptable way, and then instead they represent anomalies for the reigning theories. Not all anomalies are equally severe. Some discrepancy can always be found between theoretical predictions and experimental findings, and this does not necessarily challenge the foundations of normal science. Hence, some anomalies can be neglected, at least for some time.
Others may find a solution within the reigning theoretical framework. Only a small number will be so severe and so persistent, that they suggest the tools provided by the accepted theories must be given up, or at least be seriously modified. Even in crisis, revolution may not be immediately forthcoming.
More often though, when crisis has become severe enough for questioning the foundation, and the anomalies may be solved by a new theory, that theory gradually receives acceptance until eventually a new consensus is established among members of the scientific community regarding the new theory.
Only in this case has a scientific revolution occurred. Importantly though, even severe anomalies are not simply falsifying instances. Severe anomalies cause scientists to question the accepted theories, but the anomalies do not lead the scientists to abandon the paradigm without an alternative to replace it. Kuhn said little about this creative aspect of scientific change; a topic that later became central to cognitively inclined philosophers of science working on scientific change see the section on Cognitive Views below.
Kuhn described merely how severe anomalies would become the fixation point for further research, while attempts to solve them might gradually diverge more and more from the solution hitherto accepted as exemplary. Until, in the course of this development, embryonic forms of alternative theories were born. For Kuhn the relation between normal science traditions separated by a scientific revolution cannot be described as incorporation of one into the other, or as incremental growth. In Structure , Kuhn argued for incommensurability in perceptual terms.
But when it comes to visual gestalt-switch images, one has recourse to the actual lines drawn on the paper. For Kuhn, the change in perception cannot be reduced to a change in the interpretation of stable data, simply because stable data do not exist. Kuhn thus strongly attacked the idea of a neutral observation-language; an attack similarly launched by other scholars during the late s and early s, most notably Hanson Hanson These aspects of incommensurability have important consequences for the communication between proponents of competing normal science traditions and for the choice between such traditions.
Recognizing different problems and adopting different standards and concepts, scientists may talk past each other when debating the relative merits of their respective paradigms. But if they do not agree on the list of problems that must be solved or on what constitutes an acceptable solution, there can be no point-by-point comparison of competing theories.
Paradigm choice is a conversion that cannot be forced by logic and neutral experience. This view has led many critics of Kuhn to the misunderstanding that he saw paradigm choice as devoid of rational elements. However, Kuhn did emphasize that although paradigm choice cannot be justified by proof, this does not mean that arguments are not relevant or that scientists are not rationally persuaded to change their minds.
Aesthetic arguments, based on simplicity for example, may enter as well. Kuhn emphasized, rather, that a new paradigm often incorporates much of the vocabulary and apparatus, both conceptual and manipulative, of its predecessor. In this way, parts of the achievements of a normal science tradition will turn out to be permanent, even across a revolution.
Incommensurability is a relation that holds only between minor parts of the object domains of two competing theories. In this way, the methodological rules of a research program divide into two different kinds: a negative heuristic that tells the scientists which paths of research to avoid, and a positive heuristic that tells the scientists which paths to pursue.
On this view, all tests are necessarily directed at the auxiliary hypotheses which come to form a protective belt around the hard core of the research program. Lakatos aims to reconstruct changes in science as occurring within research programs. A research program is constituted by the series of theories resulting from adjustments to the protective belt but all of which share a hard core.
As adjustments are made in response to problems, new problems arise, and over a series of theories there will be a collective problem-shift. Any series of theories is theoretically progressive, or constitutes a theoretically progressive problem-shift, if and only if there is at least one theory in the series which has some excess empirical content over its predecessor. In the case if this excess empirical content is also corroborated the series of theories is empirically progressive.
A problem-shift is progressive, then, if it is both theoretically and empirically progressive, otherwise it is degenerate. A research program is successful if it leads to progressive problem-shifts and unsuccessful if it leads to degenerating problem-shifts.
The notion of empirical content, for instance, is carrying a pretty heavy burden in the account. In order to assess the progressiveness of a program, one would seem to need a measure of the empirical content of theories in order to judge when there is excess content. We can instead take the increase in empirical content to be a meta-methodological principle, one which dictates an aim for scientists that is, to increase empirical knowledge , while cashing this out at the methodological level by identifying progress in research programs with making novel predictions.
The importance of novel predictions, in other words, can be justified by their leading to an increase in the empirical content of the theories of a research program.
A problem-shift which results in novel predictions can be taken to entail an increase in empirical content. It remains a worry, however, whether such an inference is warranted, since it seems to simply assume novelty and cumulativity go together unproblematically. At best, anything they all have in common methodologically will be so general as to be unhelpful or uninteresting.
At any rate, Lakatos does offer us a positive heuristic for the description and even explanation of scientific change. For him, change in science is a difficult and delicate thing, requiring balance and persistence. Criticism of a program is a long and often frustrating process and one must treat budding programs leniently. In his Progress and Its Problems: Towards a Theory of Scientific Growth , Laudan defined a research tradition as a set of general assumptions about the entities and processes in a given domain and about the appropriate methods to be used for investigating the problems and constructing the theories in that domain.
The key engine driving scientific change for Laudan is problem solving. Such changes solve empirical problems, essentially those problems Kuhn conceives of as anomalies.
Severe anomalies which are not solvable merely by modification of specific theories within the tradition may be seen as symptoms of a deeper conceptual problem. In such cases scientists may instead explore what sorts of minimal adjustments could be made in the deep-level methodology or ontology of that research tradition p.
When Laudan looked at the history of science, he saw Aristotelians who had abandoned the Aristotelian doctrine that motion in a void is impossible, and Newtonians who had abandoned the Newtonian demand that all matter has inertial mass, and he saw no reason to claim that they were no longer working within those research traditions. Solutions to conceptual problems may even result in a theory with less empirical support and still count as progress since it is overall problem solving effectiveness not all problems are empirical ones which is the measure of success of a research tradition Laudan Most importantly for Laudan, if there are what can be called revolutions in science, they reflect different kinds of problems, not a different sort of activity.
For Kuhn and Lakatos, identification of a research tradition or program or paradigm could be made at the level of specific invariant, non-rejectable elements.
For Laudan, there is no such class of sacrosanct elements within a research tradition—everything is open to change over time. For example, while absolute time and space were seen as part of the unrejectable core of Newtonian physics in the eighteenth century, they were no longer seen as such a century later.
If research traditions undergo deep-level transformations of their problem solving apparatus this would seem to constitute a significant change to the problem solving activity that may warrant considering the change the basis of a new research tradition.
On the other hand, if the activity of problem solving is strong enough to provide the identity conditions of a tradition across changes, consistency might force us to identify all problem solving activity as part of one research tradition, blurring distinctions between science and non-science.
Distinguishing between a change within a research tradition and the replacement of a research tradition with another seems both arbitrary and open-ended. One way of solving this problem is by turning from just internal characteristics of science to external factors of social and historical context. Science is not just a body of facts or sets of sentences.
However one characterizes its content, that content must be embodied in institutions and practices comprised of scientists themselves. Kuhn, on the other hand, saw scientific change as a change of community and generations. While Structure may have been largely responsible for making North American philosophers aware of the importance of historical and social context in shaping scientific change, Kuhn was certainly not the first to theorize about it.
As early as the mids, Ludwik Fleck gave an account of how thoughts and ideas change through their circulation within the social strata of a thought-collective Denkkollektiv and how this thought-traffic contributes to the process of verification.
The thought-style is dogmatically transmitted from one generation to the next, by initiation, training, education or other devices whose aim is introduction into the collective. Most people participate in numerous thought-collectives, and any individual therefore possesses several overlapping thought-styles and may become carriers of influence between the various thought-collectives in which they participate. This traffic of thoughts outside the collective is linked to the most outstanding alterations in thought-content.
The ensuing modification and assimilation according to the foreign thought-style is a significant source of divergent thinking. According to Fleck, any circulation of thoughts therefore also causes transformation of the circulated thought.
Rather than helping himself to an unexamined notion of communal change, Fleck, on the other hand, made the process by which individual interacted with collective central to his account of scientific development and the joint construction of scientific thought.
What the accounts have in common is a view that the social plays a role in scientific change through the social shaping of science content. It is not a relation between scientist and physical world which is constitutive of scientific knowledge, but a relation between the scientists and the discipline to which they belong.
That relation can be restrictive of change in science. It can also provide the dynamics for change. Several philosophers of science have held the view that the dynamics of scientific change can be seen as an evolutionary process in which some kind of selection plays a central role.
One of the most detailed evolutionary accounts of scientific change has been provided by David Hull Hence, selection in the form of citations plays a central role in this account.
0コメント