The true philosophical problem does not concern the choice between realism and antirealism. It rather concerns the problem of sense, that is, of the origin of reality, its end, and relation with human beings. Experiences of sense are to be found in art, ethics, and religion. The philosophical question stems from feeling that the world, as it is or at least as it appears, is not as it ought to be. Philosophy is the attempt to explain this difference and to overcome the tension entailed in it. This can happen only within an ontology of freedom, which explains both the differentiation of being with respect to its origin and the request of being that ought to be. Three levels of reality are then in order: the original principle as pure and absolute freedom, what is there, and what ought to be. Each of them needs a different kind of knowledge.