Stathis Psillos

The recent debate around scientific realism has taken an epistemic turn. The issue is no longer whether theoretical discourse is or is not assertoric (truth-valuable), nor whether theoretical discourse can be reduced to observational discourse. All sides of the present debate have left behind traditional instrumentalism and reductive empiricism. Instead, they endorse semantic realism which suggests that theoretical discourse (that is, statements about theoretical entities) should be understood literally and be taken to be assertoric and irreducible. In this setting, the philosophical reaction to realism challenges the grounds for the realists’ belief in the existence of the unobservable entities posited by theories and in the truth of the assertions made about them. This reaction can take different shapes. But the dominant one, coming from van Fraassen’s constructive empiricism, is that an empiricist cannot be rationally forced to be a scientific realist. In his view, an empiricist can understand scientific theories literally but remain agnostic as to the truth (or falsity) of their theoretical assertions. Besides, if an empiricist decides to accept a theory he accepts it not as true but as empirically adequate.

Chakravartty claims that science does not imply any specific metaphysical theory of the world. In this sense, science is consistent with both neo-Aristotelianism and neo-Humeanism. But, along with many others, he thinks that a neo-Aristotelian outlook best suits science. In other words, neo-Aristotelianism is supposed to win on the basis of an inference to the best explanation (IBE). I fail to see how IBE can be used to favour neo-Aristotelianism over neo-Humeanism. In this essay, I aim to do two things. Firstly, I explain why this failure is not idiosyncratic: it should be there even by Chakravartty's lights. Secondly, I raise some critical worries about Chakravartty's semirealism, especially in connection with the concept of a 'concrete structure' and the detection/auxiliary distinction. The essay ends with a dilemma: an exclusive disjunction encapsulated in its title

In the present paper I want to do two things. First, I want to discuss Ramsey’s own views of Ramsey-sentences. This, it seems to me, is an important issue not just (or mainly) because of its historical interest. It has a deep philosophical significance. Addressing it will enable us to see what Ramsey’s lasting contribution in the philosophy of science was as well as what its relevance to today’s problems is. Since the 1950s, where the interest in Ramsey’s views has mushroomed, there have been a number of different ways to read Ramsey’s views and to reconstruct Ramsey’s project. The second aim of the present paper is to discuss the most significant and controversial of this reconstruction, viz., structuralism. After some discussion of the problems of structuralism in the philosophy of science, as this was exemplified in Bertrand Russell’s and Grover Maxwell’s views and has re-appeared in Elie Zahar’s and John Worrall’s thought, I will argue that, for good reasons, Ramsey did not see his Ramsey-sentences as part of some sort of structuralist programme. I will close with an image of scientific theories that Ramsey might have found congenial. I will call it Ramseyan humility.

In the present paper I want to do two things. First, I want to discuss Ramsey’s own views of Ramsey-sentences. This, it seems to me, is an important issue not just because of its historical interest. It has a deep philosophical significance. Addressing it will enable us to see what Ramsey’s lasting contribution in the philosophy of science was as well as what its relevance to today’s problems is. Since the 1950s, where the interest in Ramsey’s views has mushroomed, there have been a number of different ways to read Ramsey’s views and to reconstruct Ramsey’s project. The second aim of the present paper is to discuss the most significant and controversial of this reconstruction, viz., structuralism. After some discussion of the problems of structuralism in the philosophy of science, as this was exemplified in Bertrand Russell’s and Grover Maxwell’s views and has re-appeared in Elie Zahar’s and John Worrall’s thought, I will argue that, for good reasons, Ramsey did not see his Ramsey-sentences as part of some sort of structuralist programme. I will close with an image of scientific theories that Ramsey might have found congenial. I will call it Ramseyan humility.

The goal of this paper is to sketch an empiricist metaphysics of laws of nature. The key idea is that there are regularities without regularity-enforcers. Differently put, there are natural laws without law-makers _of a distinct metaphysical kind_. This sketch will rely on the concept of a natural pattern and more significantly on the existence of a network of natural patterns in nature. The relation between a regularity and a pattern will be analysed in terms of mereology. Here is the road map. In section 2, I will briefly discuss the relation between empiricism and metaphysics, aiming to show that an empiricist metaphysics is possible. In section 3, I will offer arguments against stronger metaphysical views of laws. Then, in section 4 I will motivate nomic objectivism. In section 5, I will address the question ‘what is a regularity?’ and will develop a novel answer to it, based on the notion of a natural pattern. In section 6, I will raise the question: ‘what is a law of nature?’, the answer to which will be: a law of nature is a regularity that is characterised by the unity of a _natural_ pattern.

Two things seem to make science different from other human activities: the existence of a special method and the claim that this method produces objective knowledge of the world. Yet, as Barry Gower’s impressive book shows, after centuries of philosophical reflection on scientific method, there is considerable disagreement as to what exactly this method is. What is more interesting is that all attempts to characterise scientific method, from Galileo and Descartes up until the present, suffer from an internal tension: whatever the method of science be in its details, it should satisfy two general desiderata which, at least prima facie, pull in contrary directions. On the one hand, it should be amplia- tive: it should be able to move from the finite data and observations available at any given time to hypotheses and theories which go far beyond these data, either by generalising them over unexamined (or even unexaminable) domains or by introducing unobserved and unobservable causes which bring the phenomena about. This ‘content-increasing’ aspect of scientific method is indispensable, if science is seen as an activity which purports to extend our knowledge beyond what is immediately observed by means of the senses. On the other hand, the method of science should be epistemically probative: it should be able to convey epistemic warrant to its conclusions (hypotheses and theories). Otherwise, its claim to extending our knowledge of the world beyond what is actually observed is dubious. The tension arises because ampliative methods don’t carry their epistemically probative character on their sleeves. Since the conclusion of an ampliative method can be false, even though all of its premises are true, the following question arises: what makes it the case that the method conveys whatever epistemic warrant the premises enjoy to the intended conclusion rather than to its negation?

Two things seem to make science different from other human activities: the existence of a special method and the claim that this method produces objective knowledge of the world. Yet, as Barry Gower’s impressive book shows, after centuries of philosophical reflection on scientific method, there is considerable disagreement as to what exactly this method is. What is more interesting is that all attempts to characterise scientific method, from Galileo and Descartes up until the present, suffer from an internal tension: whatever the method of science be in its details, it should satisfy two general desiderata which, at least prima facie, pull in contrary directions. On the one hand, it should be amplia- tive: it should be able to move from the finite data and observations available at any given time to hypotheses and theories which go far beyond these data, either by generalising them over unexamined (or even unexaminable) domains or by introducing unobserved and unobservable causes which bring the phenomena about. This ‘content-increasing’ aspect of scientific method is indispensable, if science is seen as an activity which purports to extend our knowledge beyond what is immediately observed by means of the senses. On the other hand, the method of science should be epistemically probative: it should be able to convey epistemic warrant to its conclusions (hypotheses and theories). Otherwise, its claim to extending our knowledge of the world beyond what is actually observed is dubious. The tension arises because ampliative methods don’t carry their epistemically probative character on their sleeves. Since the conclusion of an ampliative method can be false, even though all of its premises are true, the following question arises: what makes it the case that the method conveys whatever epistemic warrant the premises enjoy to the intended conclusion rather than to its negation?

The aim of this paper is to articulate, discuss in detail and criticise Reichenbach’s sophisticated and complex argument for scientific realism. Reichenbach’s argument has two parts. The first part aims to show how there can be reasonable belief in unobservable entities, though the truth of claims about them is not given directly in experience. The second part aims to extent the argument of the first part to the case of realism about the external world, conceived of as a world of independently existing entities distinct from sensations. It is argued that the success of the first part depends on a change of perspective, where unobservable entities are viewed as projective complexes vis-à-vis their observable symptoms, or effects. It is also argued that there is an essential difference between the two parts of the argument, which Reichenbach comes to accept.

Rudolf Carnap delivered the hitherto unpublished lecture ‘Theoretical Concepts in Science’ at the meeting of the American Philosophical Association, Pacific Division, at Santa Barbara, California, on 29 December 1959. It was part of a symposium on ‘Carnap’s views on Theoretical Concepts in Science’. In the bibliography that appears in the end of the volume, ‘The Philosophy of Rudolf Carnap’, edited by Paul Arthur Schilpp, a revised version of this address appears to be among Carnap’s forthcoming papers. But although Carnap started to revise it, he never finished the revision,1 and never published the unrevised transcript. Perhaps this is because variants of the approach to theoretical concepts presented for the first time in the Santa Barbara lecture have appeared in other papers of his (cf. the editorial footnotes in Carnap’s lecture). Still, I think, the Santa Barbara address is a little philosophical gem that needs to see the light of day. The document that follows is the unrevised transcript of Carnap’s lecture.2 Its style, then, is that of an oral presentation. I decided to leave it as it is, making only very minor stylistic changes—which, except those related to punctuation, are indicated by curly brackets.3 I think that reading this lecture is a rewarding experience, punctuated as the lecture is with odd remarks and autobiographical points. One can almost envisage..

Philosophy of science emerged as a distinctive part of philosophy in the twentieth century. It set its own agenda, the systematic study of the metaphysical and epistemological foundations of science, and acquired its own professional structure, departments and journals. Its defining moment was the meeting (and the clash) of two courses of events: the breakdown of the Kantian philosophical tradition and the crisis in the sciences and mathematics in the beginning of the century. The emergence of the new Frege-Russell logic, the arithmetisation of geometry and the collapse of classical mechanics called into question the neat Kantian scheme of synthetic a priori principles. But the thought that some a priori (framework) principles should be in place in order for science to be possible had still had a strong grip on the thinkers of the European continent. A heated intellectual debate started concerning the status of these a priori principles. The view that dominated the scene after the dust had settled was that the required framework principles were conventions. The seed of this thought was found in Poincaré’s writings, but in the hands of the Logical Positivists, it was fertilised with Frege’s conception of analyticity and Hilbert’s conception of implicit definitions. The consolidation of modern physics lent credence to the view that a priori principles can be revised; hence, a new conception of relativised a priori emerged. The linguistic turn in philosophy re-oriented the subject-matter of philosophical thinking about science to the language of science. Formal-logical methods and conceptual analysis were taken to be the privileged philosophical tools. Not only, it was thought, do they clarify and perhaps solve (or dissolve) traditional philosophical problems; they also make philosophy rigorous and set it apart from empirical science. In the 1930s, philosophy of science became the logic of science; it became synonymous to anti-psychologism, anti-historicism and anti-naturalism..

Thomas Brown was one of the tail-enders of the Scottish Enlightenment. He shared with Dugald Stewart the chair of Moral Philosophy at the University of Edinburgh from 1810 until his premature death in 1820. He is sometimes classed with the Scottish common-sense philosophers and, to some extent at least, his basic philosophical principles were akin to those of the common-sense philosophy. He did, for instance, forfeit the issue of the justification of some of our most basic beliefs and rested them, instead, on their being intuitively irresistible; in particular, he thought that some of our most basic beliefs could be seen as permanent principles of human nature—a claim made popular by Thomas Reid. Based on his theory of the workings of the human mind—which was developed in a course of lectures on the philosophy of mind presented at the University of Edinburgh and appeared posthumously as a book titled Lectures on the Philosophy of the Human Mind—some philosophers and psychologists have characterised him as an ‘associationist’.1 Brown ’s main contribution to the philosophy of causation was his book Inquiry into the Relation of Cause and Effect, published in 1818. This is, actually, the third edition of his little book titled Observations on.

Henri Poincaré’s views on the foundations of mechanics and the nature of mechanical explanation were influenced by the work of two of the most renowned nineteenth century scientists, James Clerk Maxwell and Heinrich Hertz. In order then to unravel Poincaré’s views and own contribution to the subject it is important to see the connection between Maxwell ’s and Hertz’s researches on the one hand and Poincaré’s on the other. Consequently, I start this paper with a brief account of Poincaré’s encounter with Maxwell ’s work in electromagnetism. Then, in section 2, I move on to show how Hertz’s work on the foundations of mechanics shaped Poincaré own views. In sections 3 and 4, I formulate Poincaré’s own conventionalist philosophy of mechanics and show how several methodological considerations, especially the search for unity, mitigated his conventionalism. Having thus examined Poincaré’s views on the foundations of mechanics, in section 5 I turn my attention to his notion of mechanical explanation and his proof that a mechanical explanation of a set of phenomena is possible if the principle of conservation of energy is satisfied. I then go on to show how Poincaré secured the possibility of a mechanical explanation of electromagnetic phenomena, and also how, having done so, he ended up with an unlimited number of configurations of matter in motion that could underpin electromagnetic phenomena. The upshot of this paper will be that Poincaré departed from the traditional conceptions on mechanical explanation and defended a purely structural conception, the strong point of which was that it promoted — as the motto of this paper says — the true and only aim of science, namely unity

P. Kyle Stanford (2000) attempts to offer a truth-linked explanation of the success of science which, he thinks, can be welcome to antirealists. He proposes an explanation of the success of a theory T1 in terms of its predictive similarity to the true theory T of the relevant domain. After raising some qualms about the supposed antirealist credentials of Stanford's account, I examine his explanatory story in some detail and show that it fails to offer a satisfactory explanation of the success of science

Among the many issues that relate to the role of Reason in science, I will focus my attention on two. The first concerns the problem of the justification of scientific method—and of induction in particular, which is the most basic and indispensable ampliative method of science. The second is related to the problem of theory-change in science: how can it be that theory-change is rational? In addressing these two issues (highlighting both their conceptual development and their present status), I will try to stress the need for a conception of method and rationality that leaves room for values.

A natural way to think of models is as abstract entities. If theories employ models to represent the world, theories traffic in abstract entities much more widely than is often assumed. This kind of thought seems to create a problem for a scientific realist approach to theories. Scientific realists claim theories should be understood literally. Do they then imply the reality of abstract entities? Or are theories simply—and incurably—false? Or has the very idea of literal understanding to be abandoned? Is then fictionalism towards scientific theories inevitable? This paper argues that scientific realism can happily co-exist with models qua abstracta

Imagine you live in 1823 and you are about to design an advanced course on the theory of heat. About fifty years ago, Lavoisier and Laplace had posited caloric as a material substance—an indestructible fluid of fine particles—which was taken to be the cause of heat and in particular, the cause of the rise of temperature of a body, by being absorbed by the body. No doubt, you rely on the best available theory, which is the caloric theory. In particular, meticulous and knowledgeable as you are, you rely on the best of the best: Laplace’s advanced account of the caloric theory of heat, with all its sophistication, detail and predictive might. You really believe that the best science teaching should be based on the best theories that are available. But you also believe that the best theory that is available is not really the best unless it has a claim to truth (or truthlikeness, or partial truth and the like). For what is the point of teaching a theory about the deep structure of the world unless it does say something or other about this deep structure? The course goes really well. Your notes are impressive. They are soon turned into a textbook with lots of explanatory detail and fancy calculations. Alas! The world does not co-operate. There are no calorific particles among the things there are in it. Heat is destroyed when work is produced. The advanced theory is challenged by alternative theories, anomalies and failed predictions. There is agony, but in your lifetime, the caloric theory gets superseded and is left discredited in the wasteland of false theories. Decades come by. You are not around anymore. Your grandchildren go to school and..

The aim of this paper is to revisit the major arguments of the seventeenth century debate concerning laws and powers. Its primary points are two. First, though the dominant conception of nature was such that there was no room for power in bodies, the very idea that laws govern the behaviour of matter in motion brought with it the following issue, which came under sharp focus in the work of Leibniz: how possibly can passive matter, devoid of power, obey laws? Though Leibniz’s answer was to re-introduce powers, two radically different conceptualisations of the relation between laws and powers became available after him. Hume denied powers altogether, whereas Newton thought that to introduce a power is to introduce a law. The second main point will be that though laws were meant to replace powers, the real dilemma ended up being not laws vs powers, but rather necessity vs non-necessity in nature. To exploit, an expression used by Newton, the question was: what is the place of necessity in the frame of nature?