Even though Leen was not involved in the founding of S.V. Arago, he still played an important role during his eleven years as faculty dean.
Besides his efforts in realising the visions, he had involving the study association – good communication between students and teachers as well as high-quality education – he also arranged a lot of the rooms in which Arago has been located. Leen never shied away from using faculty money to facilitate Arago activities that were meant to improve the quality of education.
Furthermore, he also often played the role of mediator between students, as well as between students and teachers. His involvement from day one, his pleas in the interest of Arago and a lot of other contributions have made his election as honorary member possible.