Description: I discuss the meaning of polemos - within the context of heideggerian thought - in order to emphasize the importance of the confrontation and diversity within education. A broader question that is in the background of this paper focuses on the question of how being as a Da-sein is in the polis. What are the political as well as ethical meanings of being? Since polemos is ontologically understood as the happening of Da-sein's truth in the polis, the question is thus turned to the conditions of the polis. Is polemos even possible in the polis? In other words my paper discusses the ontological aspects of truth as well as knowledge by employing the notion of polemos. The attempt is to point out the importance of a place in addition to the with-world when considering the conditions of being's polemical emplacement that is thus seen as the foundation of Being's being as such. It is hence argued that polemos establishes the authentic condition of Being's being in the polis and furthermore determines the possibilities of being-with; being in the polis is a matter of disclosing truth through polemos.My objective is to emphasize the meaning of polemos as the foundation of being in the polis. I discuss both the conditions and limits of being in the with-world in order to clarify the political sphere - which is ontological in character - of Da-sein. I argue that politics as such has established an abstract environmental space that is constantly alienating Beings; it is a reality opposed to ours and experienced through intercessors. Furthermore the ideas of democracy and citizenship, which are indisputable factors of the political reality, currently govern being and being-with in a way that annihilates their authentic ethical foundation. Nevertheless polemos - as the authentic condition of being - is something also education should respond to; I thus argue that polemos is both the ground and the end of education. In this paper I argue, by using the philosophy of Martin Heidegger, Simone de Beauvoir, Emmanuel Levinas and Luce Irigaray, that authentically being happens in a polis through polemos and yet this way of being is something both politics and education should respond to. Knowledge, and furthermore truth, do have an essential ontological dimension; polemos is the condition of understanding - of truth - in the polis. Nevertheless truth as such is thus seen as the ontological determinate that governs polis and Da-sein's authentic being. Methodology: The method I am using in my Ph.D. thesis (and which I have also used in my paper) is hermeneutical concept analysis, in which I have compounded the epistemologic-methodological hermeneutics of Friedrich Schleiermacher and the existential-phenomenological hermeneutics of Hans-Georg Gadamer (divination-tradition) in order to establish a synthesis of the philosophers' thoughts as well as to found an existential-phenomenological conception of social philosophy and social ontology. Conclusions: Overall the conclusion of my Ph.D. thesis will be that being as a Da-sein happens in the polis through polemos. This will naturally be the main point of my paper. Furthermore I will comment the traditional substances of both democracy and citizenship with the help of existential phenomenology by emphasizing the centrality of polemos. I argue that the meaning of Da-sein's polemos in the polis is conceptually understood as democratic being-with. Yet Dasein's responsibility, which can be defined as a relation between truth and care, is something that gives the substance to this democratic being-with; ethical citizenship is the element of democratic being-with. In other words, democratic being-with is the condition of an authentic Dasein but ethical citizenship is the way of its being.My objective is thus to establish a theory of Dasein's being in the polis, which in my study is entangled in the idea of polemos. In the paper I will emphasize the essentiality of polemos to citizenship education and furthermore argue that the possibility of polemos - of confrontation and diversity - is fundamental to the authentic and yet ethical human condition. To conclude, knowledge, in addition to truth, do have an essential ontological dimension; polemos is the condition of understanding - of truth - in the polis.