He did his postdoctoral work with Aron Gurwitsch and had taken classes with Dorion Cairns. He was instrumental in setting up the archives for the papers and files of, among others, Alfred Schutz, Aron Gurwitsch, and Dorion Cairns. He was a prolific scholar, having published 5 book-length investigations, 94 book chapters, 89 interpretive essays, 46 edited books, and 31 edited works of other authors. Many of his works have been published in several languages. He also gave 200 presentations in various conferences and academic settings. He served on the boards of 35 phenomenological societies and belonged to 20 philosophical societies. One of his great services was to foster the growth of phenomenological organizations worldwide, and he was frequently involved in the beginnings of such organizations, such as the Center for Advanced Research in Phenomenology, the Organization of Phenomenological Organizations, the Husserl Circle, the Círculo LatinoAmericano de Fenomenología, the Central and European Conference in Phenomenology, the Nordic Society for Phenomenology, Phenomenology for the East Asia Circle, Réseau Euro-Méditerranéen de phénoménologie pour le dialogue interculturel, the Society for Phenomenology and the Human Sciences, and the International Alfred Schutz Circle for Phenomenology and Interpretive Social Science. He was instrumental in establishing two book series, Contributions to Phenomenology (Springer Press) and the Series in Continental Thought (Ohio State University Press).
He was a great entrepreneur for phenomenology, always imagining and realizing new phenomenological projects and setting up new organizations. His service to phenomenology included encouraging the practice of phenomenological method, fostering multidisciplinary engagement, mentoring a generation of younger phenomenology scholars, and helping the tradition of phenomenology to flourish across cultures. In the many scholarly conferences he attended, he could be counted on to provide regular illuminating comments based on the views of authoritative phenomenologists, particularly those of the New School; to offer encouraging compliments and insightful criticisms; and to occasionally indulge in instances of corny humor. With Lester's death, phenomenology has lost one of its great animating spirits.