To celebrate Adolf Griinbaum's sixtieth birthday by offering him this bouquet of essays written for this purpose was the happy task of an autonomous Editorial Committee: Wesley C. Salmon, Nicholas Rescher, Larry Laudan, Carl G. Hempel, and Robert S. Cohen. To present the book within the Boston Studies in the Philosophy of Science was altogether fitting and natural, for Griinbaum has' been friend and supporter of philosophy of science at Boston University for twenty-five years, and unofficial godfather to the Boston Colloquium. To regret that we could not include contributions from all his...