This English translation of The Prodromus of Nicholaus Steno’s Dissertation is unique in that it includes an introduction and explanatory notes by John Garrett Winter and a foreword by William H. Hobbs. The introduction presents information on Steno’s life and writings, as well as a bibliography of the Prodromus. In his foreword, Hobbs advises readers to “remember that the essay was written near the middle of the seventeenth century, when scientific observation was hardly thought of.” Steno’s description of scientific observation is pioneering for his time and should appeal to those interested in the natural sciences. This volume is a publication of the University of Michigan Humanistic Series.