Dickinson S. Miller was an American ethical philosopher and epistemologist who published both under his own name and under the pseudonym R. E. Hobart. He was born in Philadelphia and studied at the University of Pennsylvania, Clark University, the universities of Berlin and Halle, Hobart College, and Harvard University. He held a doctorate in philosophy from Halle and a D.Sc. from Hobart.

At Harvard, Miller was a student of William James, who became his longtime friend and with whom he often discussed and argued points of philosophy. James was instrumental in getting Miller an appointment as associate professor of philosophy at Bryn Mawr College in 1893, the year after Miller's graduation from Harvard.

Miller left Bryn Mawr in 1898 to become first an instructor and then a professor of philosophy at Harvard. He subsequently joined the Columbia faculty, where he remained until the...