In the course of writing this dissertation on group character and jointly intentional activity, it has become abundantly clear that completing a Ph.D. is a profoundly social enterprise itself.Accordingly, I have been fortunate enough to experience a recurring theme in the literature on virtue ethics firsthand: flourishing in any social activity crucially depends on the support, wisdom, and goodwill of others. It is not surprising, then, that I owe a deep debt of gratitude to the many people who created the conditions enabling this research project to thrive.First of all, I owe warmest thanks to my primary supervisors, Boudewijn de Bruin and Miranda Fricker. I am extremely grateful for the opportunity to be a part of the Towards Professional Epistemic Justice project and work alongside such talented philosophers. You not only ensured that this project was off to a great start, but also kept it on track throughout.Managing a collaborative international research project cannot have been easy in the midst of a global pandemic, but despite all hardships you did an excellent job of making everyone involved stay connected. Thank you both for your support and encouragement.Boudewijn, I admire your philosophical rigor and your passion for applying cutting edge philosophical research to current affairs. Your detailed feedback on the many drafts of this dissertation has greatly contributed to the final product before you today. Thank you, also, for offering to collaborate with me on the Boeing chapter, and for the many other doors you have opened for me. Besides a great philosopher, you are a fantastic manager, never forgetting the people behind the work. These are lessons I will always carry with me.Miranda, your sharp philosophical insight and keen awareness of how philosophical problems pertain to contemporary social issues have inspired me from day one. The relevance of the field you pioneered fifteen years ago continues to prove itself every day, and I am deeply grateful for the opportunity to explore topics of justice, epistemology, and virtue under your supervision. Whenever I tangled myself (or my arguments) in a knot, you were invaluable in untangling them and helping me see the bigger picture. Thank you so much for all of your feedback and assistance during the last four years.During my two years at Sheffield University, I had the privilege of working with Paul Faulkner as my secondary supervisor. Paul, I am very grateful for your support, and for x detailed comments on chapters one and five of this dissertation. The brainstorming sessions we had together were incredibly fruitful, and your critical eye has been instrumental in sharpening the focus of my writing. Thank you also for being my main point of contact in Sheffield after Miranda's move to New York.As important as supervisors are, a Ph.D. cannot be completed unless it is approved by the assessment committee. Thank you, Heather Battaly, Lisa Herzog, Jeroen de Ridder, and Bob Stern, for taking the time to read this dissertation, and for subjecting it to rigo...