•  66
    Distances between formal theories
    with Mohamed Khaled, Koen Lefever, and Gergely Székely
    Review of Symbolic Logic 13 (3): 633-654
    In the literature, there have been several methods and definitions for working out whether two theories are “equivalent” or not. In this article, we do something subtler. We provide a means to measure distances between formal theories. We introduce two natural notions for such distances. The first one is that of axiomatic distance, but we argue that it might be of limited interest. The more interesting and widely applicable notion is that of conceptual distance which measures the minimum number …Read more
  •  64
    Using Mathematics to Explain a Scientific Theory
    Philosophia Mathematica 24 (2): 185-213. 2016.
    We answer three questions: 1. Can we give a wholly mathematical explanation of a physical phenomenon? 2. Can we give a wholly mathematical explanation for a whole physical theory? 3. What is gained or lost in giving a wholly, or partially, mathematical explanation of a phenomenon or a scientific theory? To answer these questions we look at a project developed by Hajnal Andréka, Judit Madarász, István Németi and Gergely Székely. They, together with collaborators, present special relativity theory…Read more
  •  63
    In this paper, we discuss the prevailing view amongst philosophers and many mathematicians concerning mathematical proof. Following Cellucci, we call the prevailing view the “axiomatic conception” of proof. The conception includes the ideas that: a proof is finite, it proceeds from axioms and it is the final word on the matter of the conclusion. This received view can be traced back to Frege, Hilbert and Gentzen, amongst others, and is prevalent in both mathematical text books and logic text boo…Read more
  •  49
    The pluralist sheds the more traditional ideas of truth and ontology. This is dangerous, because it threatens instability of the theory. To lend stability to his philosophy, the pluralist trades truth and ontology for rigour and other ‘fixtures’. Fixtures are the steady goal posts. They are the parts of a theory that stay fixed across a pair of theories, and allow us to make translations and comparisons. They can ultimately be moved, but we tend to keep them fixed temporarily. Apart from conside…Read more
  •  47
    An Analysis of the Notion of Rigour in Proofs
    Logic and Philosophy of Science 9 (1): 165-171. 2011.
    We are told that there are standards of rigour in proof, and we are told that the standards have increased over the centuries. This is fairly clear. But rigour has also changed its nature. In this paper we as-sess where these changes leave us today.1 To motivate making the new assessment, we give two illustra-tions of changes in our conception of rigour. One, concerns the shift from geometry to arithmetic as setting the standard for rig-our. The other, concerns the notion of effective proof or c…Read more
  •  42
    Are Mathematicians Better Described as Formalists or Pluralists?
    Logic and Philosophy of Science 9 (1): 173-180. 2011.
    In this paper we try to convert the mathematician who calls himself, or herself, “a formalist” to a position we call “meth-odological pluralism”. We show how the actual practice of mathe-matics fits methodological pluralism better than formalism while preserving the attractive aspects of formalism of freedom and crea-tivity. Methodological pluralism is part of a larger, more general, pluralism, which is currently being developed as a position in the philosophy of mathematics in its own right.1 H…Read more
  •  42
    On the epistemological significance of the hungarian project
    Synthese 192 (7): 2035-2051. 2015.
    There are three elements in this paper. One is what we shall call ‘the Hungarian project’. This is the collected work of Andréka, Madarász, Németi, Székely and others. The second is Molinini’s philosophical work on the nature of mathematical explanations in science. The third is my pluralist approach to mathematics. The theses of this paper are that the Hungarian project gives genuine mathematical explanations for physical phenomena. A pluralist account of mathematical explanation can help us wi…Read more
  •  34
    Most scientific theories are globally inconsistent. Chunk and Permeate is a method of rational reconstruction that can be used to separate, and identify, locally consistent chunks of reasoning or explanation. This then allows us to justify reasoning in a globally inconsistent theory. We extend chunk and permeate by adding a visually transparent way of guiding the individuation of chunks and deciding on what information permeates from one chunk to the next. The visual representation is in the for…Read more
  •  28
    Inconsistency in Mathematics and Inconsistency in Chemistry
    Humana Mente 10 (32): 31-51. 2017.
    In this paper, I compare how it is that inconsistencies are handled in mathematics to how they are handled in chemistry. In mathematics, they are very precisely formulated and identified, unlike in chemistry. So the chemists can learn from the precision and the very well-worked out strategies developed by logicians and deployed by mathematicians to cope with inconsistency. Some lessons can also be learned by the mathematicians from the chemists. Mathematicians tend to be intolerant towards incon…Read more
  •  24
    Pluralism and “Bad” Mathematical Theories: Challenging our Prejudices
    In Francesco Berto, Edwin Mares, Koji Tanaka & Francesco Paoli (eds.), Paraconsistency: Logic and Applications, Springer. pp. 277--307. 2013.
  •  11
    Second-order logic is logic
    Dissertation, St. Andrews. 1997.
    "Second-order logic" is the name given to a formal system. Some claim that the formal system is a logical system. Others claim that it is a mathematical system. In the thesis, I examine these claims in the light of some philosophical criteria which first motivated Frege in his logicist project. The criteria are that a logic should be universal, it should reflect our intuitive notion of logical validity, and it should be analytic. The analysis is interesting in two respects. One is conceptual: it…Read more
  •  6
    Hilbert’s axiomatic approach to the sciences was characterized by a dynamic methodology tied to scientific and mathematical fields under investigation. In particular, it is an analytic art for choosing axioms but, at the same time, it has to include dynamically synthetic procedures and meta-theoretical reflections. Axioms have to be useful, or capture something, or help as part of explanations. The Andréka-Németi group use several formal axiomatic theories together to re-capture, predict, recove…Read more
  •  5
    I present a formal language that imposes a structure on processes in macro-chemistry. Each symbol in the language invites a type of analysis that is carried out either by looking into the semantics if the language or by looking at the context. Every formal language has assumptions underlying it. The assumptions made in developing the formal language are meant to help with conceptual analysis by inviting certain types of question.
  •  5
    What is mathematics about? Does the subject-matter of mathematics exist independently of the mind or are they mental constructions? How do we know mathematics? Is mathematical knowledge logical knowledge? And how is mathematics applied to the material world? In this introduction to the philosophy of mathematics, Michele Friend examines these and other ontological and epistemological problems raised by the content and practice of mathematics. Aimed at a readership with limited proficiency in math…Read more
  •  5
    I present a formal language that imposes a structure on processes in macro-chemistry. Each symbol in the language invites a type of analysis that is carried out either by looking into the semantics if the language or by looking at the context. Every formal language has assumptions underlying it. The assumptions made in developing the formal language are meant to help with conceptual analysis by inviting certain types of question.
  •  4
    I present a formal language that imposes a structure on processes in macro-chemistry. Each symbol in the language invites a type of analysis that is carried out either by looking into the semantics if the language or by looking at the context. Every formal language has assumptions underlying it. The assumptions made in developing the formal language are meant to help with conceptual analysis by inviting certain types of question.
  •  4
    The phrase ‘mathematical foundation’ has shifted in meaning since the end of the nineteenth century. It used to mean a consistent general theory in mathematics, based on basic principles and ideas to which the rest of mathematics could be reduced. There was supposed to be only one foundational theory and it was to carry the philosophical weight of giving the ultimate ontology and truth of mathematics. Under this conception of ‘foundation’ pluralism in foundations of mathematics is a contradictio…Read more
  •  3
    Editor's Note by Michele Friend
    Foundations of Chemistry 25 (3): 343-344. 2023.
  •  3
    Varieties of Pluralism and Objectivity in Mathematics
    Journal of the Indian Council of Philosophical Research 34 (2): 425-442. 2017.
    Realist philosophers of mathematics have accounted for the objectivity and robustness of mathematics by recourse to a foundational theory of mathematics that ultimately determines the ontology and truth of mathematics. The methodology for establishing these truths and discovering the ontology was set by the foundational theory. Other traditional philosophers of mathematics, but this time those who are not realists, account for the objectivity of mathematics by fastening on to: an objective accou…Read more
  •  3
    Measuring ecologically sound practice in the chemical industry
    Foundations of Chemistry 1-11. forthcoming.
    I present a comparative and holistic method for qualitatively measuring sound ecological practice in chemistry. I consider chemicals developed and used by man from cradle to grave, that is, from the moment they are extracted from the earth, biomass, water or air, to their transportation, purification, mixing and elaboration in a factory, to their distribution by means of the market, to waste products both from the factory, packaging, transportations and by the consumer. I divide the locations of…Read more
  •  3
  • Leigh S. Cauman, First-order Logic, an Introduction (review)
    Philosophy in Review 20 240-244. 2000.
  • Preface
    Journal of the Indian Council of Philosophical Research 34 (2): 205-207. 2017.