Thinking about boundaries and self-knowledge

What are conditions of possibility of thinking about boundaries? When we are speaking of boundaries, it means that we know both side of them, without such a presupposition we can’t know boundaries and can’t speak meaningfully about them. This ‘knowledge of both sides’ is the most important epistemological condition of possibility of thinking about boundaries. This article tries to analyze this epistemological Condition and its anthropological (or ontological) conditions; it tries to explain the role of human existence and its specialties in this context and through it, attempt to disclose key function of thinking about boundaries for self-knowledge which is core of Socrates definition of philosophy.