Referee's comment: 'This book will be a rewarding reading for everybody who is interested in logical aspects of scientific knowledge acquisition. The presentation of the issues discussed in the book is exemplary. ...I hardly could mention another book in which various philosophical viewpoints on the nature of scientific inquiry are discussed in such a consistent but at the same time instructive and accurate way. ...I am quite sure that Hendricks' approach to the problems he studies is of considerable interest for anybody who is interested in forming a good theoretical model of growth of science.'