The authors of this book are members of EBM+ (ebmplus.org), a network of researchers investigating the role of evidence of mechanisms in the health sciences. During the writing of this book, Parkkinen, Wallmann, Wilde and Williamson were based at the Centre for Reasoning, University of Kent; Clarke, Illari and Norell at the Department of Science and Technology Studies, UCL; Kelly at the Department of Public Health and Primary Care, University of Cambridge; Russo at the Department of Philosophy, University of Amsterdam; and Shaw at the National Institute of Health and Care Excellence, UK. This research way supported by the UK Arts and Humanities Research Council and the Leverhulme Trust.