I would like to record my thanks to Paul Thompson for useful conver- sations over the years, and also to several generations of students who have helped me develop my ideas on biological theory and on Darwin. My wife has, as usual, been more than helpful; in particular she typed a good portion of the manuscript while I was on leave a few years ago, more now than I like to remember. My parents were both looking forward to holding a final copy of this book. I only regret that my mother did not live long enough to see its completion. I must also thank the publishers and their staff. They have...

The essays collected in this volume represent, in a revised version, the pa pers of the Wittgenstein Conference held in November 1989 at the Univer sity ofRome 'La Sapienza' to celebrate the centenary ofhis birth. They offer a systematic account ofWittgenstein's philosophy ofmind and contribute to illuminate his later conception of perceptive, emotional and cognitive lan guage. Some of the reasons why it seemed the right time to promote an am pIe confrontation ofideas on Wittgenstein's mature perspective are sufficiently c1ear as they derive from the need to sum up the state of research based...

Approach your problems from the right end It isn't that they can't see the solution. It is and begin with the answers. Then one day, that they can't see the problem. perhaps you will find the final question. G. K. Chesterton. The Scandal of Father 'The Hermit Clad in Crane Feathers' in R. Brown 'The point of a Pin'. van Gulik's The Chinese Maze Murders. Growing specialization and diversification have brought a host of monographs and textbooks on increasingly specialized topics. However, the "tree" of knowledge of mathematics and related fields does not grow only by putting forth new branches....

The history of the rare earths has entered its third century; trans uranium elements are now a half century old. Both the lanthanide and actinide ele- ments, 30 elements altogether, are f elements, meaninj that their metallic 2 1 1 electronic configurations are typically 6s 5d 4f" and 7s 6d 5f" respectively. To an elementary approximation as summarized in the 'average inorganic chemistry textbook, these configurations cause their chemistry to be described by the trivalent state accompanied by less interesting effects such as the lanthanide contraction. However, the discovery of divalent and...

The papers included in this volume were presented at the symposium on "Americium and Curium Chemistry and Technology" at the International Chemical Congress of Pacific Basin Societies in Honolulu, Hawaii, December 16-21, 1984. This symposium commemorated forty years of research on americium and curium. Accordingly, the papers included in this volume begin with historical perspectives on the discovery of americium and curium and the early characterization of their chemical properties, and then cover a wide range of subjects, such as thermodynamic properties, electronic structure, nuclear...