"Seek ye first the good things of the mind," Bacon admonishes us, "and the rest will either be supplied or its loss will not be felt. 引自 Introduction
This is why I love philosophy. The rest will fall properly in the seats around philosophy.
Specifically, philosophy means and includes five fields of study and discourse: logic, esthetics, ethics, politics, and metaphysics.
Logic is the study of ideal method in thought and research: observation and introspection, deduction and induction, hypothesis and experiment, analysis and synthesis - such are the forms of human activity which logic tries to understand and guide; it is a dull study for most of us, and yet the great events in the history of thought are the improvements men have made in their methods of thinking and research.
Esthetics is the study of ideal form, or beauty; it is the philosophy of art.
Ethics is the study of ideal conduct; the highest knowledge, said Socrates, is the knowledge of good and evil, the knowledge of the wisdom of life.
Politics is the study of ideal social organization (it is not, as one might suppose, the art and science of capturing and keeping office); monarchy, aristocracy, democracy, socialism, anarchism, feminism - these are the dramatis personae of political philosophy.
Lastly, metaphysics is the study of the "ultimate reality" of all things: of the real and final nature of "matter" (ontology) of "mind" (philosophical psychology), and of interrelation of "mind" and "matter" in the processes of perception and knowledge (epistemology). 引自 Introduction
Very clear division of philosophy sub-disciplines
What is the importance of philosophy?
For me personally, I think with so many years of development of philosophy. Whatever a non-philosopher think cannot jump outside of the philosophies available. The more understanding of philosophy, the better one can understand the origin of other people's personal philosophy.