An early stage in the evolution of Aristotle's physics

Aristotle's Physics V and VI deal with the same concepts: motion, change and continuity. The two books, however, employ altogether different approaches to the study of these concepts, thus presenting different orders of conceptualization. Abraham Edel (1982, 42) claims that Aristotle is a systematic philosopher “not in the sense of [i] one who pursues a deductive system … but in the sense of [ii] one who has a well-constructed and fairly clearly analyzed conceptual network that he uses with considerable power in field after field of human inquiry.” Truly, [ii] is more typical of Aristotle, but in the Physics both approaches are present. Books VI and V (respectively) are good examples. It is commonly taken for granted that Physics V prepares for VI, because of the order in which they appear in the corpus, and because V includes the definitions of the main concepts that are used in VI. A closer look at the texts, however, reveals that the definitions of V are not used in VI. I argue that the definitions of V were not only unknown when VI was written, but are actually incompatible with the spirit of Physics VI and with the main thesis underlying it. Physics VI is close in method, conceptual basis and in its radical formal approach to the Posterior Analytics, and a part of it (the early stratum) looks like a mathematical exercise. The mathematical-logical approach was abandoned, and gave way to the more mature Aristotelian style, which is already dominant in Physics V.     

Public scientific testimony in the scientific image

In this paper, I draw on philosophy of science to address a challenge for science communication. Empirical research indicates that some people who trust a meteorologist's report that they are in the path of a storm do not trust a climate scientist's report that we are on a path to global warming. Such selective skepticism about climate science exemplifies a more general challenge:

The Challenge of Selective UptakeLaypersons who generally accept public scientific testimony nevertheless fail to accept public scientific testimony concerning select, equally well warranted, scientific hypotheses.

A prominent response arising from the novel interdisciplinary science of science communication is a principle called Consensus Reporting. According to this principle, science reporters should, whenever feasible, report the scientific consensus or lack thereof for a reported scientific view.However, philosophy of science may offer a different perspective on the issue. This perspective is critical insofar as it indicates some inadequacies of Consensus Reporting. But it is also constructive insofar as it guides the development of an alternative principle, Justification Reporting, according to which science reporters should, whenever feasible, report aspects of the nature and strength of scientific justification or lack thereof for a reported scientific view. A central difference between these proposals is that Consensus Reporting appeals to the authority of the scientists whereas Justification Reporting appeals to the authority of scientific justification. As such, Justification Reporting reflects the image of science.The paper considers the philosophical and empirical motivation for Justification Reporting and its limitations. This includes prospects and problems for implementing it in a way that addresses The Challenge of Selective Uptake. From a methodological point of view, the paper illustrates how empirically informed philosophy of science may help address challenges for science communication.     

Isoelectrically focused carboxyesterases as a biological marker in chimeras

Summary Species-specific multiple forms of carboxyesterases (CE) were determined in zymograms obtained by isoelectric focusing (IEF) using homogenized wing zeugopodal tissues of chick, quail and quail-chick chimeras. The validity of the CE pattern of chimeric tissues was verified by the nuclear marker technique. Analytical IEF of CE was found to be useful for investigation of the origin of tissues in chimeras.Acknowledgment. This work was supported by grant AM21026.     

Extensional scientific realism vs. intensional scientific realism

Extensional scientific realism is the view that each believable scientific theory is supported by the unique first-order evidence for it and that if we want to believe that it is true, we should rely on its unique first-order evidence. In contrast, intensional scientific realism is the view that all believable scientific theories have a common feature and that we should rely on it to determine whether a theory is believable or not. Fitzpatrick argues that extensional realism is immune, while intensional realism is not, to the pessimistic induction. I reply that if extensional realism overcomes the pessimistic induction at all, that is because it implicitly relies on the theoretical resource of intensional realism. I also argue that extensional realism, by nature, cannot embed a criterion for distinguishing between believable and unbelievable theories.     

Hempel on scientific understanding

Hempel seems to hold the following three views: (H1) Understanding is pragmatic/relativistic: Whether one understands why X happened in terms of Explanation E depends on one's beliefs and cognitive abilities; (H2) Whether a scientific explanation is good, just like whether a mathematical proof is good, is a nonpragmatic and objective issue independent of the beliefs or cognitive abilities of individuals; (H3) The goal of scientific explanation is understanding: A good scientific explanation is the one that provides understanding. Apparently, H1, H2, and H3 cannot be all true. Some philosophers think that Hempel is inconsistent, while some others claim that Hempel does not actually hold H3. I argue that Hempel does hold H3 and that he can consistently hold all of H1, H2, and H3 if he endorses what I call the “understanding argument.” I also show how attributing the understanding argument to Hempel can make more sense of his D-N model and his philosophical analysis of the pragmatic aspects of scientific explanation.