Giuseppe Peano (27 August 1858 – 20 April 1932) was an Italian mathematician, logician, and one of the founders of modern mathematical logic and set theory. His work, summarized in Formulario mathematico (1895) was highly influential and the standard Peano axioms of the natural numbers are named in his honor.

Questions that pertain to the foundations of mathematics, although treated by many in recent times, still lack a satisfactory solution. Ambiguity of language is philosophy's main source of problems. That is why it is of the utmost importance to examine attentively the very words we use. — Arithmetices Principia, nova methodo exposita [The Principles of Arithmetic, presented by a new method] (1889)

Giuseppe Peano — Notations de Logique Mathématique (1894), p. 173, as quoted in "The Mathematical Philosophy of Giuseppe Peano" by Hubert C. Kennedy, in Philosophy of Science Vol. 30, No. 3 (July 1963)

Giuseppe Peano — "Sui fondamenti della geometria" (1894), p. 141, as quoted in "The Mathematical Philosophy of Giuseppe Peano" by Hubert C. Kennedy, in Philosophy of Science Vol. 30, No. 3 (July 1963)

Giuseppe Peano — Geometric Calculus (1895) as translated by Lloyd C. Kannenberg (2000) "The Operations of Deductive Logic'" Ch. 1 "Geometric Formations"

Giuseppe Peano — As expressed in Galileo's Finger: The Ten Great Ideas of Science (2003) by Peter Atkins, Ch. 10 "Arithmetic : The Limits of Reason", p. 333