the primary beneficiary is the individual educated or the society having this individual as its member. Many of the more specific discussions in the philosophy of education concern the contents of the curriculum. This involves the questions of whether, when, and in what detail a certain topic, like sex education or religion, should be taught. Other debates focus on the specific contents and methods used in moral, art, and science education. Some philosophers investigate the relation between education and power, often specifically regarding the power used by modern states to compel children to attend school, a practice rejected by some advocates of the movements of deschooling and unschooling. A different issue is the problem of the equality of education, i.e. the demand that all students should be treated equally in public education. This is often understood in the sense that education should open the same opportunities to everyone. This ideal is threatened by various sources of inequality, like active discrimination and unequal distribution of wealth. In regard to educational research, some philosophers of education promote a quantitative approach, which follows the example of the natural sciences by using wide experimental studies. Others prefer a qualitative approach, which is closer to the methodology of the social sciences and tends to give more prominence to individual case studies. A topic that came to particular prominence in the contemporary discussion is the role of standardized testing in public schools. Various schools of philosophy have developed their own perspective on the main issues of education. Existentialists emphasize the role of authenticity while pragmatists give particular prominence to active learning and discovery. Feminists and postmodernists often try to uncover and challenge biases and forms of discrimination present in current educational practices. Other philosophical movements include perennialism, classical education, essentialism, critical pedagogy, and progressivism. The history of the philosophy of education started in ancient philosophy and has remained an important topic to the present day. Despite its long and diverse history, it only emerged as a systematic branch of philosophy in the latter half of the 20th century. In universities, the philosophy of education usually forms part of departments or colleges of education. Definition The philosophy of education is the branch of philosophy that examines the nature, aims, and problems of education. As the philosophical study of education, it investigates its topic similar to how other discipline-specific branches of philosophy, like the philosophy of science or