Series 1. Essays and Lecture notes, 1907 - 1915

Includes: Costello's Psychology I. notebook from 1907 (Earlham College, undergraduate studies); handwritten seminar papers and essays from 1909 to 1911, titled ‘Some partly neglected aspects of the free-will controversy’; ‘External relations and the “argument from Missouri”’; ‘Individuality and value: A study of the relation of individuality to ethical means and ends’; ‘The nature of means and ends in ethics’; ‘The significance of the concept of relative efficiency’ [for J. Royce’s seminar]; and various notes.