Gregory Landini is Professor of Philosophy at the University of Iowa, USA. He is the author of four books on the founding
figures of analytic philosophy, including the groundbreaking Russell's Hidden Substitutional Theory in 1998 - explaining how
the early substitutional logic of Russell's type-free ontology of propositions, which was planned for his never realized second
volume of The Principles of Mathematics (1903) evolved into the "no-propositions" simple type formal grammar of Principia
Mathematica (1910). It's sequel, Wittgenstein's Apprenticeship with Russell (2007) argues that Wittgenstein's Tractarian doctrines
were offered in alliance with Russell's 1914 program for scientific method in philosophy with an emulation of Principia's
logic as its essence. Together with his book Russell (2010), all three earned Bertrand Russell Society Book Awards. The fourth
book, Frege's Notations: What they are and how they mean (2012) is in Palgrave Macmillan's History of Analytic Philosophy
Series. Landini has written many scholarly articles on Russell, including "Whitehead's (Badly) Emended Principia" and "Typos
of Principia Mathematica" in History and Philosophy of Logic, "Russellian Facts About the Slingshot" in Axiomathes, and "Zermelo
and Russell's Paradox: Is There a Universal Set?" and "Logicism and the Problem of Infinity: The Number of Numbers" in Philosophia
Mathematica. He is a director of the Bertrand Russell Society.
Landon D. C. Elkind is a graduate student in philosophy
at the University of Iowa, USA. He is treasurer of the Bertrand Russell Society and of the Society for the Study of the History
of Analytical Philosophy. His dissertation, In Defense of Logical Atomism, concerns both the necessary features of the underlying
logic of logical atomism and what doctrines are essential to logical atomism, especially in light of its historical development.