In this provocative work, David N. Stamos tackles the problem of determining exactly what a biological species is: in short, whether species are real and the nature of their reality. Although many have written on this topic, The Species Problem is the only comprehensive single-authored book on this central concern of biology. Stamos critically considers the evolution of the three major contemporary views of species: species nominalism, species as classes, and species as individuals. Finally, he develops his own solution to the species problem, a solution aimed at providing a universal species concept worthy of the Modern Synthesis. This book will be of interest to philosophers of biology and of science in general, to historians of biology, and to biologists concerned with one of the most significant (and practical) conceptual issues in their field.

"Stamos' study deserves high praise. It is the most comprehensive survey of the literature on the question of "species" - how to define the term, how to classify it among other biological terms, how it was historically used and misused, how it relates to other questions of ontology (what there is) and epistemology (what do we know and how we get to know it), and how it is bound with serious philosophical questions about Universals (do they exist?, are they nothing but a collection of Individuals?) and Essentialism (does something have certain characteristics that are essential or secondary to its very nature and existence?), to name just two categories. The book is well organized, clearly written, broadly researched, and meticulously referenced…as such, this book should become a standard reference to anyone interested in biology form theoretical and practical perspectives alike." - Bridges