 Philosophy of education is the branch of applied or practical philosophy concerned with the nature and aims of education and the philosophical problems arising from educational theory and practice. Because that practice is ubiquitous in and across human societies, its social and individual manifestations so varied, and its influence so profound, the subject is wide-ranging, involving issues in ethics and social/political philosophy, epistemology, metaphysics, philosophy of mind and language, and other areas of philosophy. Because it looks both inward to the parent discipline and outward to educational practice and the social, legal, and institutional contexts in which it takes place, philosophy of education concerns itself with both sides of the traditional theory/practice divide. Its subject matter includes both basic philosophical issues (e.g., the nature of the knowledge worth teaching, the character of educational equality and justice, etc.) and problems concerning specific educational policies and practices (e.g., the desirability of standardized curricula and testing, the social, economic, legal and moral dimensions of specific funding arrangements, the justification of curriculum decisions, etc.). In all this the philosopher of education prizes conceptual clarity, argumentative rigor, the fair-minded consideration of the interests of all involved in or affected by educational efforts and arrangements, and informed and well-reasoned valuation of educational aims and interventions.