Philosophy of education is a specialized area of educational inquiry which provides a unique perspective on educational policy, research and practice: that of the professional critic. This reflective stance has three characteristic features. First, it is foundational. It asks basic questions about the meaning, value and limits of knowledge. So, for example, a philosopher wonders not about how dyslexic children learn but investigates the criteria practitioners use to diagnose dyslexia. Second, it is humane. This interest in basic questions is not idle speculation and it does not relish scepticism. Philosophers think that understanding the world truthfully can help us sort out how to live well. An appreciation of the value of reading complements knowledge about how to teach reading. Only the former shows how we can use reading to enrich human beings' lives. Third, philosophy is promiscuous. All domains of knowledge are open to philosophical scrutiny. Philosophy of education's legitimacy as a branch of modern philosophy derives from being foundational, humane reflection brought to the domain of education.