Philosophy

Recently, I have read some books about philosophy. I found books about philosophy are really hard to understand. After reading these books, it seemed that I had learned a lot of theories about philosophy. However, I know not what I learned now. I am even more confused than before. What is philosophy is a highly controversial topic. There are much more controversial issues in every theory system. So obviously I need to spend more time and energy to learn philosophy.
Let me introduce some basic knowledge about philosophy.
There are a lot of branches of philosophy. The following branches are the main areas of study:
Metaphysics investigates the nature of being and the world. Traditional branches are cosmology and ontology.
Epistemology is concerned with the nature and scope of knowledge, and whether knowledge is possible. Among its central concerns has been the challenge posed by skepticism and the relationships between truth, belief, and justification.
Ethics, or 'moral philosophy', is concerned with questions of how persons ought to act or if such questions are answerable. The main branches of ethics are meta-ethics, normative ethics, and applied ethics. Meta-ethics concerns the nature of ethical thought, comparison of various ethical systems, whether there are absolute ethical truths, and how such truths could be known. Ethics is also associated with the idea of morality. Plato's early dialogues include a search for definitions of virtue.
Political philosophy is the study of government and the relationship of individuals and communities to the state. It includes questions about justice, the good, law, property, and the rights and obligations of the citizen.
Aesthetics deals with beauty, art, enjoyment, sensory-emotional values, perception, and matters of taste and sentiment.
Logic deals with patterns of thinking that lead from true premises to true conclusions, originally developed in Ancient Greece. Beginning in the late 19th century, mathematicians such as Frege focused on a mathematical treatment of logic, and today the subject of logic has two broad divisions: mathematical logic (formal symbolic logic) and what is now called philosophical logic.
Philosophy of mind deals with the nature of the mind and its relationship to the body, and is typified by disputes between dualism and materialism. In recent years there has been increasing similarity between this branch of philosophy and cognitive science.
Philosophy of language is the reasoned inquiry into the nature, origins, and usage of language.
There are two kinds of philosophy which are quite different .they are western philosophy and eastern philosophy. Two important nations which contributed a lot are Germany and China.
The main theories of philosophy includes realism and nominalism , rationalism and empiricism, skepticism, idealism, pragmatism and so on.
Some famous philosophers: Plato, René Descartes, Immanuel Kant, Søren Kierkegaard,
Ferdinand de Saussure.
http://en.wikipedia.org/wiki/Philosophy#Existentialism