Concept
Definitions of philosophy aim at determining what all forms of philosophy have in common and how to distinguish philosophy from other disciplines. Many different definitions have been proposed but there is very little agreement on which is the right one. Some general characteristics of philosophy are widely accepted, for example, that it is a form of rational inquiry that is systematic, critical, and tends to reflect on its own methods. But such characteristics are usually too vague to give a proper definition of philosophy. Many of the more concrete definitions are very controversial, often because they are revisionary in that they deny the label philosophy to various subdisciplines for which it is normally used. Such definitions are usually only accepted by philosophers belonging to a specific philosophical movement. One reason for these difficulties is that the meaning of the term "philosophy" has changed throughout history: it used to include the sciences as its subdisciplines, which are seen as distinct disciplines in the modern discourse. But even in its contemporary usage, it is still a wide term spanning over many different subfields. An important distinction among approaches to defining philosophy is between deflationism and essentialism. Deflationist approaches see it as an empty blanket term, while essentialistic approaches hold that there is a certain set of characteristic features shared by all parts of philosophy. Between these two extremes, it has been argued that these parts are related to each other by family resemblance even though they do not all share the same characteristic features. Some approaches try to define philosophy based on its method by emphasizing its use of pure reasoning instead of empirical evidence. Others focus on the wideness of its topic, either in the sense that it includes almost every field or based on the idea that it is concerned with the world as a whole or the big questions. These two approaches may also be combined to give a more precise definition based both on method and on topic.