The term "philosophy" derives from a combination of the Greek words "philos" meaning love and "sophia" meaning wisdom; literally the love of wisdom or knowledge.Philosophers ask questions about the most general and abstract features of the world and categories with which we think: mind, matter, reason, proof, and truth. In philosophy, the concepts with which we approach the world themselves become the topic of enquiry such as reality, causation, belief, right and wrong, beauty, self, God, and law. The realm of philosophy encompasses the systematic inquiry of the fundamental questions concerning, among other things, the nature of reality (metaphysics), the nature of knowledge (epistemology), the conduct of life (ethics) and the structure of argument (logic).The study of philosophy involves forming one's own views about life's questions and their answers. Philosophers also seek understanding of the way people have answered such questions in the past. In studying the history of philosophy one explores the ideas of historical figures such as the following:

"The unexamined life is not worth living."
- Socrates

"It is the mark of an educated mind to be able to entertain a thought without accepting it." - Aristotle

"Love takes up where knowledge leaves off."
- Saint Thomas Aquinas

"Except our own thoughts, there is nothing absolutely in our power."
- René Descartes

"The effect is totally different from the cause, and consequently can never be discovered in it." - David Hume

"The understanding does not derive its laws (a priori) from, but prescribes them to, nature" - Immanuel Kant

"Everyone who receives the protection of society owes a return for the benefit."
- John Stuart Mill

"Existence precedes essence."
- Jean-Paul Sartre