Decio Krause

This book addresses the logical aspects of the foundations of scientific theories. Even though the relevance of formal methods in the study of scientific theories is now widely recognized and regaining prominence, the issues covered here are still not generally discussed in philosophy of science. The authors focus mainly on the role played by the underlying formal apparatuses employed in the construction of the models of scientific theories, relating the discussion with the so-called semantic approach to scientific theories. The book describes the role played by this metamathematical framework in three main aspects: considerations of formal languages employed to axiomatize scientific theories, the role of the axiomatic method itself, and the way set-theoretical structures, which play the role of the models of theories, are developed. The authors also discuss the differences and philosophical relevance of the two basic ways of aximoatizing a scientific theory, namely Patrick Suppes’ set theoretical predicates and the "da Costa and Chuaqui" approach. This book engages with important discussions of the nature of scientific theories and will be a useful resource for researchers and upper-level students working in philosophy of science.

This book addresses the logical aspects of the foundations of scientific theories. Even though the relevance of formal methods in the study of scientific theories is now widely recognized and regaining prominence, the issues covered here are still not generally discussed in philosophy of science. The authors focus mainly on the role played by the underlying formal apparatuses employed in the construction of the models of scientific theories, relating the discussion with the so-called semantic approach to scientific theories. The book describes the role played by this metamathematical framework in three main aspects: considerations of formal languages employed to axiomatize scientific theories, the role of the axiomatic method itself, and the way set-theoretical structures, which play the role of the models of theories, are developed. The authors also discuss the differences and philosophical relevance of the two basic ways of aximoatizing a scientific theory, namely Patrick Suppes’ set theoretical predicates and the "da Costa and Chuaqui" approach. This book engages with important discussions of the nature of scientific theories and will be a useful resource for researchers and upper-level students working in philosophy of science.

Can quantum particles be regarded as individuals, just like books, tables and people? According to the 'received' view - articulated by several physicists in the immediate aftermath of the quantum revolution - quantum physics itself tells us they cannot: quantum particles, unlike their classical counterparts, must be regarded as 'non-individuals' in some sense. However, recent work has indicated that this is not the whole story and that the theory is also consistent with the position that such particles can be taken to be individuals, albeit at a metaphysical price. Drawing on philosophical accounts of identity and individuality, as well as the histories of both classical and quantum physics, the authors explore these two alternative metaphysical packages. In particular, they argue that if quantum particles are regarded as individuals, then Leibniz's famous Principle of the Identity of Indiscernibles is in fact violated. Recent discussions of this conclusion are analysed in detail and, again, the costs involved in saving the Principle are carefully considered. Taking the alternative package, the authors deploy recent work in non-standard logic and set theory to indicate how we can make sense of the idea that objects can be non-individuals. The concluding chapter suggests how these results might then be extended to quantum field theory. Identity in Physics brings together a range of work in this area and further develops the authors' own contributions to the debate. Uniquely, as the title indicates, it situates this work in the appropriate formal, historical, and philosophical contexts.

Can quantum particles be regarded as individuals, just like books, tables and people? According to the 'received' view - articulated by several physicists in the immediate aftermath of the quantum revolution - quantum physics itself tells us they cannot: quantum particles, unlike their classical counterparts, must be regarded as 'non-individuals' in some sense. However, recent work has indicated that this is not the whole story and that the theory is also consistent with the position that such particles can be taken to be individuals, albeit at a metaphysical price. Drawing on philosophical accounts of identity and individuality, as well as the histories of both classical and quantum physics, the authors explore these two alternative metaphysical packages. In particular, they argue that if quantum particles are regarded as individuals, then Leibniz's famous Principle of the Identity of Indiscernibles is in fact violated. Recent discussions of this conclusion are analysed in detail and, again, the costs involved in saving the Principle are carefully considered. Taking the alternative package, the authors deploy recent work in non-standard logic and set theory to indicate how we can make sense of the idea that objects can be non-individuals. The concluding chapter suggests how these results might then be extended to quantum field theory. Identity in Physics brings together a range of work in this area and further develops the authors' own contributions to the debate. Uniquely, as the title indicates, it situates this work in the appropriate formal, historical, and philosophical contexts.