- Empiricism in mathematics
- History and philosophy of geometry
— Geometric reasoning in the 19th century
- Pasch's philosophy of mathematics
— Pasch and Klein on the role of intuition in proofs
— Pasch's views on logic
- Mathematical cognition
— Numeral systems
— Reasoning with logical notations
- Paul Bernays:
Editor and translator of papers on philosophy of mathematics by Paul Bernays (Bernays Project).
- Rudolf Carnap:
— Editor (with E. Reck and G. Schiemer) of volume 3, Pre-Syntax Logic 1927-1934, of The Collected Works of Rudolf Carnap.
— Editor (with Warren Goldfarb) of volume 5, Logical Syntax of Language, of The Collected Works of Rudolf Carnap.
- David Hilbert:
— Editor, David Hilbert's Lectures on the Foundations of Mathematics and Physics, 1891 to 1933. Volume 2: David Hilbert's Lectures on the Foundations of Arithmetic and Logic. Edited by William Ewald, Michael Hallett, Wilfried Sieg, and Ulrich Majer.
- Moritz Pasch:
— Weierstrass' lectures on analytic functions (1865/66). With Rachel Rudolph.
— Lectures on Modern Geometry (1882/1926) (translation).
— On the educational value of mathematics (1894) (translation).
- My Erdös number (Collaboration Distance to Paul Erdös) is at most 4 (August 2011).
- Co-founder of the Montreal Inter-University Workshop on History and Philosophy of Mathematics.
- Research Keywords: Analogical reasoning, axiomatics, Bernays, Carnap, Dedekind, discovery, Hilbert, history of algebra, history of geometry, neural networks, mathematical practice, model-based reasoning, numeral systems, Pasch, Roman numerals.
History and Philosophy of Mathematics:
- Association for the Philosophy of Mathematical Practice (APMP)
- Canadian Society for History and Philosophy of Mathematics (CSHPM)
- Association of Symbolic Logic (ASL)
- Philosophy of Mathematics Association (PMA)
- Practice and Cultures of Mathematics
History and Philosophy of Science:
- Canadian Society for History and Philosophy of Science (CSHPS)
- International Society for the History of Philosophy of Science (HOPOS)
- Philosophy of Science Association (PSA)