 After the retirement of W. Jenkin Jones in 1932, Aaron was appointed to the chair of philosophy at Aberystwyth University where he settled, initially on the nearby hill of Bryn Hir and later at Garth Celyn.Although his early publications focused on epistemology and the history of ideas, Aaron became fascinated with the work and life of John Locke.The interest was sparked by his discovery of unexamined information in the Lovelace Collection