The main point of reference in this research paper is the author's declaration that he finds the question about the essence of the human being in toto nonsensical. This declaration - radical in its tone - may for the reader uninitiated into the works of O.F. Bollnow, an author of many anthropological and hermeneutic works and treatises - seem paradoxical at first. This declaration is inextricably linked with Bollnow's postulate that anthropological attempts at creating a closed and transparent image of man should be abandoned not only on account of cognitive difficulties, but also due to moral responsibility. This study is the evidence of the reflection on the reasons determining Bollnow's restrained attitude towards the possibilities for defining the human being in terms of essence. At the same time, it emphasises the cognitive results of the author's considerations on the consequences of the lack of the essence-wise defining of man in Bollnow's philosophical inquiries, and on how else one can pursue an "anthropological mode of deliberations" with a view to fruitful results and without slipping into the rut of traditional philosophical anthropology, which after all has many a time posed the issue of essence-wise determination of man. In his conception of the essence-wise openness of man, Bollnow resembles Helmuth Plessner's viewpoint on man as an open problem.