Pieri and the Italian school of geometers[edit]The Italian mathematician Mario Pieri (1860–1913) took a different approach and considered a system in which there were only two primitive notions, that of point and of motion.[31] Pasch had used four primitives and Peano had reduced this to three, but both of these approaches relied on some concept of betweeness which Pieri replaced by his formulation of motion. In 1905 Pieri gave the first axiomatic treatment of complex projective geometry which did not start by building real projective geometry.
Pieri was a member of a group of Italian geometers and logicians that Peano had gathered around himself in Turin. This group of assistants, junior colleagues and others were dedicated to carrying out Peano's logico–geometrical program of putting the foundations of geometry on firm axiomatic footing based on Peano's logical symbolism. Besides Pieri, Burali-Forti, Padoa and Fano were in this group. In 1900 there were two international conferences held back-to-back in Paris, the International Congress of Philosophy and the Second International Congress of Mathematicians. This group of Italian mathematicians was very much in evidence at these congresses, pushing their axiomatic agenda.[32] Padoa gave a well regarded talk and Peano, in the question period after David Hilbert's famous address on unsolved problems, remarked that his colleagues had already solved Hilbert's second problem.