This volume contains symposium papers presented at the nineteenth biennial meeting of the Philosophy of Science Association (PSA) held in Austin, Texas, November 18–20, 2004.

Thanks are due to many people who made the meeting successful. Sandra Mitchell, PSA 2002 program chair, generously helped with her recent experience and knowledge of PSA practices and customs. George Gale, PSA secretary-treasurer, coached us on procedures, opportunities and deadlines and helped to plan the presidential reception. And Elliott Sober, PSA president 2003–2004, was active in advising me and the PSA2004 Program Committee throughout the process. I thank each of you for your support and counsel. Jay Malone in the History of Science Society office provided assistance for registration and local arrangements.

The PSA2004 Program Committee worked diligently to select an excellent and balanced set of symposium proposals. Each proposal was refereed by every member of the Program Committee, and often comments were sent to authors. I thank each member of the Program Committee for their service to PSA: Christina Bicchieri, David Hilbert, Carl Hoefer, Harold Kincaid, Fred Kronz, Roberta Millstein, Alan Richardson, and Andrea Woody.

The online submission and evaluation software was managed by Temple University philosophy graduate student Micah Sparacio. Micah creatively adapted the program OpenConf to our needs and hosted the Web site. Thanks to Micah's expertise, the software operated with a minimum of glitches and no disasters. My thanks also to Susan Herbst, dean of the College of Liberal Arts, Temple University, for allotting Micah a modest stipend for this work.

After PSA2004, Michael Dickson and his staff, Liz Stillwaggon and Holly Groover in the office of Philosophy of Science, took over the work of collection and final preparation of the papers for publication. I thank them for so seamlessly taking over the publication of the journal from the previous editor Noretta Koertge and for expanding the scope of its operations to include so much of the editorial work for the PSA2004 volumes.

Finally, I thank the PSA for the opportunity to chair the PSA2004 Program Committee. It was a worthwhile, interesting experience. A full report of the work of the Program Committee and its recommendations for future conferences is available from me by request.

Miriam Solomon

Department of Philosophy, Temple University