This document consists primarily of excerpts (chapters 5 and 10-12) from the author’s book From Brain to Cosmos. These excerpts address several traditional problems about the histories of conscious subjects, using the concept of subjective fact that the author developed earlier in the book. Topics include the persistence of conscious subjects through time, the unity or disunity of the self, and the possibility of splitting conscious subjects. (These excerpts depend heavily upon the author’s concept of subjective fact as developed in From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of that book first. See the last page of this document for details on how to obtain those chapters.)