This book is based on my dissertation »Killing to Prevent Killings? – An Exemplary Discussion of Deontic Restrictions’ Place, Point, and Justifiability«, on the merits of which I received my doctorate on 23 February 2018 from the Faculty of Philosophy of the Humboldt University in Berlin (then under the direction of Dean Prof. Dr. Gabriele Metzler). I would like to seize the opportunity of this preface to express my gratitude to a number of people without whom the completion of this work would not have been possible. First of all, I would like to thank my supervisor and first assessor, Prof. Dr. Kirsten Meyer, who made this project possible to begin with. It was her encouragement that made me plunge into that endeavour called ›PhD‹ in the first place. Her support over the years, in matters both organisational and philosophical, provided the soil on which this work could grow. The role of my second assessor, Prof. Dr. Christoph Fehige, in the emergence of this thesis was very different – and yet of potentially equal import. I first met Christoph, when I was still an undergrad student at the University of Bayreuth. Ever since then, his philosophical rigour and precision, his enthusiasm, and his whole approach to philosophical argument should serve as a steady inspiration for my own work – such that I was very glad to hear that he would be willing to take on the role of a second assessor for my thesis. Talking about supervisors, I am here inclined to also mention Dr. Maike Albertzart. While she had no official role in the making of this work, her unfaltering advice and encouragement, her willingness to discuss both philosophical niceties as well as the greater picture were surely beyond what one could expect from a colleague – and I still hope not to have strained her patience too much. The gratitude I feel for the support of my friend Constantin Stroop is of no lesser extent. Over the years, he never failed to have a sympathetic ear for my many concerns, academic or beyond, and without the advice he offered during countless lunch-breaks, I am not sure whether I would ever have been able to get through and finish this project. Finally, I would like to thank all those who contributed to the completion of this work in one way or another and who, I hope, will not take the fact of their names being simply enlisted here to imply that my gratitude would be small; in particular I am thinking of Vuko Andrić, Katrin von Boltenstern, Simon Deichsel, Jan Gertken, Jonas Harney, Benjamin Kiesewetter, Nora Kreft, Jan Krumnow, Leo Menges, Johanna Privitera, Dörte Rokitta-Krumnow, Samuel Scheffler, Lukas Tank, Stefanie Thiele, Marcel Twele, Ulla Wessels, and Susanna Wittmann-Gering. Furthermore, my thanks go to the members of the colloquia of my supervisor, Prof. Dr. Kirsten Meyer, and of her colleague, Prof. Dr. Thomas Schmidt, as well as to the participants of the PhD-colloquium at the Chair of Practical Philosophy at Saarland University in June 2015.
Last but not least, it should not be forgotten that a PhD requires funding, and I would like to thank the German Business Foundation (»Stiftung der Deutschen Wirtschaft«) and the German Academic Scholarship Foundation (»Studienstiftung des Deutschen Volkes«) for their generous financial support.