Interdisciplinary integration at theological faculties, as envisaged in the apostolic constitution Veritatis Gaudium, is a demanding challenge. The empirical-experimental method of the natural sciences, which is based on measurable quantities and their mathematisation, is finding its way into research in the social sciences and humanities. The status of science vis-à-vis philosophy or theology can thus be challenged, which makes the dialogue and interdisciplinary cooperation between different sciences, which is necessary for a holistic understanding of people and their actions, more difficult. The development of psychology is driven by the desire to understand people, their emotions and their actions. To achieve these goals, concepts from philosophy and psychology about people and their function are constantly supplemented by new information from empirical research. The article shows the development of family therapy, which is represented in various study programmes at the Faculty of Theology at the University of Ljubljana. A particular example of interdisciplinary integration is the study programme Human and Interpersonal Relationships, which combines the fields of theology, religion, psychology and therapy.