Philosopher
A philosopher, in a wide sense, is someone who studies philosophy. The term "philosopher" comes from the Ancient Greek φιλόσοφος (philosophos), which means "lover of wisdom". The introduction of the terms "philosopher" and "philosophy" has been ascribed to the Greek thinker Pythagoras.
A philosopher, in the more narrow and common usage, is any intellectual who has made contributions in one or more current fields of philosophy, such as aesthetics, ethics, epistemology, logic, metaphysics, social theory, and political philosophy. A philosopher may also be one who worked in the humanities or other sciences which have since split from philosophy proper over the centuries, such as the arts, history, economics, sociology, psychology, linguistics, anthropology, theology, and politics. They may relate this knowledge to the discussion of philosophical problems.
In the classical sense, a philosopher is someone who lives according to a way of life, whose focus is upon resolving existential questions about the human condition, and not someone who discourses upon theories or comments upon authors. Typically, these particular brands of philosophy are Hellenistic ones and those who most arduously commit themselves to this lifestyle may be considered philosophers.