I examine Richard Dedekind's important contributions to set theory. These contributions
are made in his mathematical work and I present an exposition of several of his mathematical
papers. I develop my paper in the following sections:
¶ 1. Dedekind's first contacts with the concept of set [1855-1858]
¶ 2. The manuscript of 1858 and the paper of 1872
¶ 3. «Supplement X» of Dirichlet's Lectures on Number Theory, second edition [1871]
¶ 4. The text of 1888 and the manuscript of 1872-1878
¶ 5. An unpublished manuscript of 1887-1897: the dangers of set theory
¶ 6. The unpulished manuscripts of 1887 and 1889
¶ 7. Dedekind and topology
¶ 8. Conclusion
¶ and I show that Dedekind's contributions to set theory are very important and that without them
possibly the introduction of set theory into mathematicical work might have appeared later that it did.