This paper is a revised version of the introductory lecture presented at the ECLAS Conference in Ljubljana in 1991. It attempts to outline the ontological framework of landscape architecture as a discipline encompassing two distinctive fields of creative work: planning and design. The author is of the opinion that this dual nature of landscape architecture is largely established and is of crucial importance to the future evolution of the profession and its strategic position in society. At the same time there is a marked variety in understanding of the nature of the profession, and also of the underlying concepts for educational programmes. This calls for more conceptual thinking and further elaboration.