A major project of his later years was a large-scale work intended to provide a systematic overview of literary studies. Five volumes were planned, with the title "Die Wissenschaft von der Dichtung". The first set of two volumes, entitled "Werk und Dichter" (loosely, "Poets and their works") was published in 1939. The second set, consisting of three volumes, was entitled "Dichtung in Raum und Zeit" (loosely, "Poetry in Space and Time"). It was still unpublished when he died, but it proved possible to add some final detailed corrections from the manuscripts and publish it posthumously in 1944, expended to include an introduction, by Erich Trunz, whose own academic career took off, in some respects, at the point at which Petersen's had ended.
