"In an earlier era of "natural philosophy', physics and philosophy of physics were quite inseparably intertwined, but in the modern age of proliferating specialization, fruitful communication across the disciplines has become the exception rather than rule. We would like to think that the workshop¹ and this volume are symptomatic of an ongoing process of reunification, one which can pave the way toward exceptional progress in this fundamental and highly challenging area, and others as well" — the editors Richard A. Healey and Geoffrey Hellman write in the Preface. The main topic of the ten articles in this volume, Quantum Measurement, indeed, requires both physical and philosophical considerations.