Acknowledgements.- Preface.- 1. BSE - A LEAP INTO THE UNKNOWN.- 1.1 Introduction.- 1.2 Transmissible Spongiform Encephalopathies.- 1.3 The BSE Knowledge Problem.- Notes.- 2 THE SCIENTIFIC CHALLENGE.- 2.1 Introduction.- 2.2 The Current Paradigm in Epidemiology.- 2.3 Early Epidemiological Investigations.- Notes.- 3 ARGUING THROUGH UNCERTAINTY.- 3.1 Introduction.- 3.2 Presumption and Science.- 3.3 Presumption and Uncertainty Management.- 3.4 Presumption,...