Note from the Editor

This issue of Perspectives on Science is slightly different from our normal presentation. In addition to the Review by Marjorie Grene, we offer three sets of papers, each of which opens up a line of discussion on a topic of deep and abiding interest. The discussion between Professors Sabra and Saliba on issues in the history of Arabic astronomy proves once again that the history of science remains a fertile area of research and that disagreements among major scholars is how progress is made. Kevin Elliott and Kristin Shrader-Frechette provide us with new insights into the phenomenon of "hormesis," concerning the positive effects of low doses of chemicals or radiation that are toxic at higher doses. Finally, the exchange between Esther-Mirjam Sent and Mie Augier over the question of the consistency of Herbert Simon's intellectual trajectory reveals the value of contextualizing historical analyses even in cases of recent history. This discussion also serves as a reminder of the richness of Simon's thought and how much he will be missed. The rigor of all of these presentations and the range of issues and topics they present reflect the scope of the journal and are a testament to the high quality of the work it attracts. We hope you agree.

Joseph C. Pitt

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