ABSTRACT
In the present volume, it is less clear than it was in Volumes 2, 3, and 4 of these Collected Papers that a large quantity of material written by Russell during the period of the volume has been lost. Nevertheless, it is likely that, in this volume too, much such material is no longer extant. One factor suggesting such a loss is the files ra 230.031230 (171 leaves) and ra 230.031240 (104 leaves), which are miscellaneous parts of drafts of Principia Mathematica (PM). The first file has many fragments, each of which consists of a few consecutively numbered folios, almost all of which contain numbered propositions and their demonstrations in logical notation with very little in English; five coherent parts of it are printed as Papers 23a-e. The second file has unnumbered leaves, and one leaf among them, largely in English, is printed as Paper 4d. But most of the material in those two files is not included in this volume.
