We are very sad to relate the news that Sam Epstein died on November 29, 2019 at his home. Epstein was the Marilyn J. Shatz Collegiate Professor of Linguistics and Cognitive Science at the University of Michigan. He obtained his Ph.D. from the Department of Linguistics at the University of Connecticut in 1987, writing a thesis titled, “Empty Categories and Their Antecedents.” Epstein went on to become one of the most influential figures in modern syntactic theory. He produced a number of ground-breaking works which are considered to be classics of the field. This for example holds for his 1999 paper “Un-principled Syntax: The Derivation of Syntactic Relations”. C-command has always been considered to be one of the most fundamental syntactic relations. Until that paper, no one really knew why, which left the whole field in a rather uncomfortable position: there was an ever present relation that fundamentally affected almost all syntactic phenomena and we did not understand why that was the case. In the paper in question, Epstein proposed an amazingly elegant and simple deduction of c-command which also explained why c-command is so pervasive. It was, and still is, an example of syntactic theorizing at its best. That paper and Epstein’s work more generally (e.g., books A Derivational Approach to Syntactic Relations and Derivations in Minimalism) led to a fundamental change in the syntactic theory, with derivationality and derivational mechanisms being emphasized over representational mechanisms. The field simply would not have been the same without Epstein.