In his notes for teaching the Advanced Logic class at Harvard in spring 1914, Costello quoted from Russell 5 passages of advice for the course. They total several sentences. Given Costello's letter to BR of 8 November 1913 (record 779) asking about his teaching assignment in preparation for BR's arrival, it is assumed that the passages are from BR's reply to Costello.

[The notes, titled "Philosophy 21: Advanced Logic, Harvard University, 1914", were discovered by Bernard Linsky and deposited at McMaster in image and typed formats in Rec. Acq. 1741. See pp. 4-5 for the quoted passages. Linsky is working on a project to publish the notes. In the meantime, they are not for public use.]