Quoted from the introduction: “In a letter to David Hilbert, datelined January 27, 1900, Georg Cantor takes a position against Dedekind’s opinion that numbers are “free creations of the human mind” (“free” underlined by Cantor), and the editors comment as follows: In der Überzeugung, dass Zahlen auch transiente Realität besitzen […], besteht denn auch die wesentliche Differenz zu Dedekind, dem die Zahlen “freie Schöpfungen des menschlichen Geistes” sind. “Es ist der Gegensatz zwischen dem “Finden und Entdecken” einerseits und dem “Erfinden oder Schöpfen” andererseits, der in den Auffassungen dieser beiden Mathematiker zum Ausdruck kommt.”
This quotation is to be found on the pages 428 and 429 of [G. Cantor, Briefe. Hrsg. von Herbert Meschkowski und Winfried Nilson. Berlin etc.: Springer-Verlag (1991; Zbl 0743.01031)].
The themes above have been worked out in sections with titles as:
1) Number as an idea;
2) Gauß (1777–1855), number theory and science for itself;
3) Carl Gustav Jacobi (1804–1851) and the number’s honour;
3.1) Philology and the unity of science;
3.2) Novalis and mathematics as a religion;
4) Kummer (1810–1893), religion and the ideal of freedom;
5) Dedekind (1831–1916), “en état de Créateur absolu”;
6) Conclusion: Leibniz and no end.
In summary: this paper describes the wrestling of classical authors in mathematical and philosophical aspects on the creation and appearances of the concepts of the notion of “number”.
The paper deserves to be read. Many insights have been established.
For the entire collection see [Zbl 1237.01001].