Online research in philosophy

I take Newton's arguments to inverse square centripetal forces from Kepler's harmonic and areal laws to be classic deductions from phenomena. I argue that the theorems backing up these inferences establish systematic dependencies that make the phenomena carry the objective information that the propositions inferred from them hold. A review of the data supporting Kepler's laws indicates that these phenomena are Whewellian colligations-generalizations corresponding to the selection of a best fitting curve for an open-ended body of data. I argue that the information theoretic features of Newton's corrections of the Keplerian phenomena to account for perturbations introduced by universal gravitation show that these corrections do not undercut the inferences from the Keplerian phenomena. Finally, I suggest that all of Newton's impressive applications of Universal gravitation to account for motion phenomena show an attempt to deliver explanations that share these salient features of his classic deductions from phenomena.

In this article, I compare two varieties of abduction as reconstructive models for analysing discovery. The first is 'Hansonian abduction', which is based on N. R. Hanson's formulations of abduction. The other is 'Harmanian abduction', the Inference to the Best Explanation (IBE) model, formulated especially by Gilbert Harman. Peter Lipton has analysed processes of discovery on the basis of his developed form of Harmanian abduction. I argue that Hansonian abduction would, however, be a more apt model for this purpose. As an example, I reconstruct, in a Hansonian manner, Ignaz Semmelweis's research on childbed fever and compare it to the IBE reconstruction of Lipton. I argue that Hansonian abduction is in accordance with Lipton's aim of taking into account the distinction between actual and potential explanations on the one hand, and between likely and lovely explanations on the other. I maintain that a developed version of Hansonian abduction combined with loveliness gives an important, new conceptual means for analysing processes of discovery.

The phenomenon we now know as projection was first observed by Frege in his brief remarks about presupposition in “Sense and Reference.” Frege observes there that the assertion that Kepler died in misery gives rise to the implication that the name Kepler has a referent; but that so too does the assertion that Kepler did not die in misery. Here we have the source of the observation that if p is a presupposition of S, then p is implied by (utterances of) S and by (utterances of) the negation of S. Since Frege, it has been observed that those implications which are shared by a sentence S and by its negation are also typically shared by a variety of other entailment-canceling embeddings of S: in questions, in the antecedents of conditionals, and under epistemic possibility modals. This observation has entered the canon in the form of the “family of sentences” test (Chierchia and McConnell-Ginet 2000). This test is 1 standardly used to demonstrate that some particular element of content projects. An application of the test is demonstrated below.

After a brief comparison of Aliseda’s account with different approaches to abductive reasoning, I relate abduction, as studied by Aliseda, to idealization, a notion which also occupies a very important role in scientific change, as well as to different ways of dealing with the growth of scientific knowledge understood as a particular kind of non-monotonic process. A particularly interesting kind of abductive reasoning could be that of finding an appropriate concretization case for a theory, originally revealed as extraordinarily success-ful but later discovered to be strictly false or only approximately or ideally true. I try to show this with the example of the Kepler-Newton relation. At the end of the paper, I give criteria in order to construe abduc-tive explanations in correspondence with a reasonable account of empirical progress.

: This study of the concept of orbit is intended to throw light on the nature of revolutionary concepts in science. We observe that Kepler transformed theoretical astronomy that was understood in terms of orbs [Latin: orbes] (spherical shells to which the planets were attached) and models (called hypotheses at the time), by introducing a single term, orbit [Latin: orbita], that is, the path of a planet in space resulting from the action of physical causes expressed in laws of nature. To demonstrate the claim that orbit is a revolutionary concept we pursue three lines of argument. First we trace the origin of the term; second, we document its development and specify the meaning of the novel term as it was introduced into astronomy by Kepler in his Astronomia nova (1609). Finally, in order to establish in what sense the concept is revolutionary, we pay attention to the enduring impact that the concept has had on the relevant sciences, in this case astronomy and indeed physics. We claim that orbit is an instance of a revolutionary concept whose provenance and use can provide the insights we are seeking.

This paper argues that Kepler considered his work in optics as part of natural philosophy and that, consequently, he aimed at change within natural philosophy. Back-to-back with John Schuster’s claim that Descartes’ optics should be considered as a natural philosophical appropriation of innovative results in the tradition of practical and mixed mathematics the central claim of my paper is that Kepler’s theory of optical imagery, developed in his Paralipomena ad Vitellionem (1604), was the result of a move similar to Descartes’ by Kepler. My argument consists of three parts. First, Kepler borrowed a geometrical model and experiment of optical imagery from the mélange of mixed and practical mathematics provided in the works of the sixteenth-century mathematicians Ettore Ausonio and Giovanni Battista Della Porta. Second, Kepler criticized the Aristotelian theory of light and he developed his own alternative metaphysics. Third, Kepler used his natural philosophical assumptions about the nature of light to re-interpret the model of image formation taken from Della Porta’s work. Taken together, I portray Kepler’s theory of optical imagery as a natural philosophical appropriation of an innovative model of image formation developed in a sixteenth-century practical and mixed mathematical tradition which was not interested in questioning philosophical assumptions on the nature of light.

Atocha Aliseda’s Abductive Reasoning (2006) gives a structural characterization of the “forward” explana-tory reasoning from a theory to observational data. This paper asks whether there are any interesting structural rules for the “backward” abductive reasoning from observations to explanatory theories. Ignoring statistical cases, a partial explication of abduction is converse deductive explanation: h is abducible from e iff h deductively explains e. This relation of abducibility trivially satisfies Converse Entailment (if h entails e, then h is abducible from e ), but it does not generally satisfy Converse Consequence (if h is abducible from e and g entails h, then g is abducible from e ), since deductive explanation is not always transitive.

: This paper offers my current view of a joint research project, with Bernard R. Goldstein, that examines Kepler's unification of physics and astronomy. As an organizing theme, I describe the extent to which the work of Kepler led to the appearance of the form of Copernicanism that we accept today. In the half century before Kepler's career began, the understanding of Copernicus and his work was significantly different from the modern one. In successive sections I consider the modern conception of Kepler's contribution to Copernicanism, the most influential sixteenth century view of Copernicus's work and its sequel, Kepler's work from the viewpoint of this tradition, and finally the historical origins of the modern view of Copernicanism.

First, this article provides a survey of the kind of relationship that existed between Kepler and the Jesuits. Afterwards, it is pondered upon the likelihood of their having been in direct contact with each other while Kepler lived in Prague. The second part of the article is devoted to an investigation into the correspondence between Kepler and Paul Guldin as an example. Thus, the paper describes the key issues of those letters and concludes from this Guldin's attitude to Kepler and the resulting commitment to Kepler's affairs. Finally, the article examines whether the assumption that Kepler and Guldin later discontinued their correspondence intensionally is verifiable and plausible.