“I am not trying to make some new meaning from these films; I am striving to bring out the meanings that are there but obscured by the plot lines,” Thom Andersen writes of the method he employed for his film Juke: Passages from the Films of Spencer Williams (2015). Again and again, Andersen’s movies about movies—Red Hollywood (co-directed with Noël Burch, 1996), Los Angeles Plays Itself (2003), The Thoughts That Once We Had (2015)—repeat this action, like racking focus: suddenly drawing attention to something we had always seen onscreen but hadn’t paid attention to, excavating histories, geographies, and ideas we didn’t know we’d missed. Unsurprisingly, Slow Writing, the new collection of Andersen’s writings on cinema, is like his films: measured, political, a little bit ornery, striving to bring forward similarly…