The goal of philosophy is to address the “big questions” that do not fall into other disciplines: how people should act (ethics), what exists (metaphysics), how individuals know what they know (epistemology), and how people should reason (logic). Originating from Greek, the word means “love of wisdom.”
Historically, philosophy has been a catch-all for academic subjects that don’t fit into the traditional disciplines of science and the humanities. This doesn’t mean it is disconnected from these areas, however, and in fact, the relationship between this field and science is almost as close as the relationship between math and science, and many masters of literature have also started philosophical movements. Many academic disciplines have a corresponding philosophy behind them. Less formally, it is just a way of thinking about something.
The discipline is thought to have truly begun under Socrates, an ancient Greek philosopher who is often considered the most famous and important philosopher of all time. He developed the Socratic method, a general technique for looking at philosophical problems based on definition, analysis, and synthesis. Back in Socrates’ time and up until the Scientific Revolution in the 17th century, philosophy and science were often practiced by the same people and considered two parts of the same discipline. Science was called “natural philosophy” — a way of thinking about the world.
In the domain of ethics, people may consider questions like whether or not it is ethical to save the life of a murderer, if he may kill again. Philosophers debate such questions for hours, creating doctrines to help organize and justify their own opinions. Within the domain of ethics, there is disagreement about whether or not there exists an objective morality: an objectively correct way to do things that is superior to any other. At the opposite end of the spectrum, a philosopher may ask if everything is relative. If morality is arbitrary, why should people have one at all?
Metaphysics looks at the first causes and principles of things, as well as the relationship between consciousness and the world. Many questions previously considered metaphysical, like “how did the universe come into existence?” have fallen into the domain of science, being revealed through hypotheses and experiment. Some metaphysical questions, however, may not have scientific answers. Some scientists would argue back that a non-scientific answer to such questions is not really an answer at all.
Epistemology looks at the roots of knowledge. Since the human mind is just representations of the external world rather than perfect reflections of it, how can people know anything outside of our minds? Answering this question is the responsibility of epistemology. Like metaphysics, epistemology often overlaps with science or statistics, especially in the area of probability theory.
Logic is what kickstarted mathematics, and it continues to play an important role in many disciplines. Through probability theory, logic can be formalized in a more quantitative way, and these findings have been applied to the creation of more intelligent software programs. One day, studies in logic may lead to a design for a logical machine.