This paper is about the notion of conflict in the work of John Dewey. Special attention is given to "Democracy and Education" (1916) because of its centennial and its acclaimed status of "magnum opus". After depicting "conflicts as gadflies" that stir thinking--reflection and ingenuity--and relating it to Socrates, in particular, we present a definition of conflict that guides our research. From then on a detailed analysis is carried out on the different notions of conflict in "Democracy and Education". It is concluded that Dewey spends considerable attention to the place of conflict in education in "Democracy and Education". We identified 14 distinct references to conflict. The notions range from conflicts between traditional and modern education, retrospective and prospective aims of education, the conflict between closing off and opening up of education, social and national aims of education, conflicts between certain knowledge and thinking, between ready-made and problem-posing education, between holding to customs and tradition or aiming at social change, between easy to chew education or allowing to make mistakes, between researching contrary beliefs or following proclaimed truth, conflicts between individual aims or the aim of society, and vocational versus intellectual education. Conflicts are conditional for "reflection and ingenuity" is Dewey's most iconic conception of conflicts. Conflicts challenge thought by questioning and doubting certain knowledge. The act involves a risk. We ask two questions at the end of this paper. The first is about the nature of contradictions and the second is about the use of conflicts in education. We propose that Dewey was too engaged in resolving contradictions and dualism to understand the positive, constructive, and conditional nature of conflicts for education. We need our opponents to grow and we suggest that we probably do not use them enough in education. Concerning the practical use of conflicts in education, Dewey expects a lot from dialogical cooperation and communication which will bring agreement and certainty. Dewey does not engage in confronting power, though he has a clear view on injustice in society, neither does he give prolific directions for including conflicts as a teaching method in education.