David Hull, who died in August, is the person most responsible for the philosophy of biology achieving the status within philosophy that it has today. He is the single figure most responsible for its flourishing. He also had profound and positive effects on the working of its internal culture and the priorities seen in research. David was born in 1935 and grew up in the midwest of the USA. He lived in the midwest, especially the Chicago area, for almost his whole life. He did his graduate work in the early 1960s, in History and Philosophy of Science, in the visionary department at Indiana University. He taught at just two universities, the University of Wisconsin at Milwaukee (1964 to 1984) and Northwestern (1984 to 2000). He lived openly as a gay man from the early 1960s. When David began work, biology was often treated in the philosophy of science as an afterthought. Physics provided the subject-matter and test cases for almost all of the most influential work. David Hull, along with Michael Ruse, William Wimsatt, and some others, changed this, and the change seemed to start the moment Hull finished graduate school. Hull's philosophical work divides into three main strands. The first is seen in his earliest published work, which appeared in the mid 1960s. This work focused on classification in biology, and the relation between classification and evolutionary theory. Hull was both wise and fortunate in choosing this as an area of interest, as classification (or "systematics") became philosophically interesting in several distinct ways during the...