An Egg Is an Egg Is an Egg

typical historian of biology, either. Her recent books, even though they draw heavily on historical evidence, are not histories in the strict sense. Keller is highly selec-Making Sense of Life: Explaining Biological Development tive in her choice of material and she does not write with Models, Metaphors, and Machines extensively documented monographs on a topic. Rather, her style is essayistic with all the advantages Cambridge, MA: Harvard University Press (2002). and disadvantages of this particular genre. The essay 388 pp. $20.97 format, often and unjustly maligned in science, suits On a recent long flight from Vienna to Phoenix, returning Keller well in her pursuits, such as trying to understand from a conference on the legacy of the famed Prater how scientific explanations are constructed, communi-Vivarium and the Viennese Roots of Theoretical Biology, cated, and finally accepted, as well as in her attempts I had plenty of time to ponder Evelyn Fox Keller's most to identify the generative role of language and meta-recent book Making Sense of Life and its topic, what it phors in that process. Once she identifies a particular means to " understand " in developmental biology. After thread, such as the notion of the gene, she then follows three days of discussions focusing on the close connec-it through different layers of meaning and signification. tions between experimental and theoretical biology dur-The result is always stimulating, even though it often ing the first decades of the 20 th century, a phenomenon leaves the reader yearning for a more systematic and that was especially prominent in the context of develop-comprehensive treatment of the subject. mental biology, I was, at first, struck by the many omis-At the heart of all of Keller's studies lies the fundamen-sions in Evelyn Fox Keller's work. It is indeed " idiosyn-tal epistemological question of what constitutes an ex-cratic " (p. xi), as the author claims in her Preface. I will planation in biology. While this is intrinsically a philo-discuss some of the problems I had with this book be-sophical question, it is also a historical one. It is obvious low, but first, by means of introduction I would like to to everybody, and not just to students of the history of situate Evelyn Fox Keller's work within recent discus-biology, that the evaluation criteria for scientific explana-sions in the history and philosophy of biology as well tions have changed through time. And it is equally true …