This is by no means a comprehensive introduction to philosophy, but it contains the basics. This is not what you would get by taking an intro philosophy course, mostly because at no point in any philosophy course would you typically get an introduction like this. These topics would be covered but never in a simple systematic way.
If physics is the study of how things move, and how the universe works, then philosophy is the study of how we think, and how we view the universe.
There are three main branches of philosophy: Metaphysics, Epistemology, and Ethics.
Metaphysics deals with how we fundamentally understand how the universe works, and what makes up the universe. This sets what we consider to be "allowable". This includes things like whether matter is made up of atoms, strings, the four elements, or plum pudding. But it also includes how we view consciousness, the mind, and how we think.
If you want to know the metaphysics of a person then ask them to define, or describe consciousness. The answer they give will not tell you anything about what consciousness actually is, but it will teach you about their metaphysics.
Metaphysics can be broken down into several (sometimes non-exclusive) broad categories. Dualism is the idea that there are two (or dual) components to reality. The material, or physical world, and the world of "the mind" or spirit, or rational thought. Monism is the idea that there is only one nature and both matter and the mind derive from the same source. Materialism is the idea that everything is the result of the fundamental laws of physics and the interactions of particles. Materialists deny that "the mind" is a separate thing apart from the firing of neurons in the brain. Materialists are by definition monists, but not all monists are materialists. One example of non-materialist monists are Mormons. Classical Christianity, Islam, and a few other worldviews are fundamentally dualist.
Epistemology deals with how we know, and know about the world. Perhaps Professor Truman G. Madsen, who spent five decades dealing with philosophical questions, put it best when he said, "There are really only five main modes that have been appealed to in all the traditions, philosophical or religious: an appeal to reason, an appeal to sense experience, to pragmatic trial and error, to authority—the word of the experts—and, finally, to something a bit ambiguous called 'intuition.'."
Science falls squarely under the umbrella of epistemology. If anyone gets into a discussion about what science fundamentally is, it ultimately rests on an endorsement of a particular epistemology, and nothing else. On a fundamental level, science does not have a preferred metaphysics* or ethics.
Logic is a subset of epistemology, and is not synonymous with it.
Ethics deals with what we value. Your ethics determines how you interact with other people and animals, and occasionally things. This area of philosophy is usually the messiest and most contentious.
Ethics is strongly related to Aesthetics, since what we value is generally what we find beautiful, and what we enjoy is what we value.
A huge portion of religion deals with ethical questions.
These three, Metaphysics, Epistemology, and Ethics are all related to each other, and mutually supportive, and occasionally at odds with each other. That is, our metaphysics determines our epistemology and ethics. While our epistemology informs us of our metaphysics and ethics, while our ethics reveals our metaphysics and epistemology. One cannot have a particular metaphysics without a corresponding epistemology, nor ethics. Because once one is set the others will automatically be defined.
The short descriptions I have given above are by no means exhaustive, nor are the examples I gave all there is. The key is to know that there are these three parts to philosophy, and they are interconnected, related, codependent, reinforcing, and co-determining. They are also by no means static. The particular metaphysics, epistemology, and ethics of someone will definitely change over time.
Also it is possible, and very likely, for someone to have a particular metaphysics, epistemology, or ethics, and not be able to explain or articulate their thought, any more than most people could give a complex breakdown and accounting of their diet, including any and all nutrients. It is also possible to have the particular implementation of one of the three be incompatible with the others (people who smoke may also exercise).
But generally the position of any one of the three will determine the other two. The interrelationships are complex and usually take a great deal of effort of understand.
Most changes in someone's philosophy are subtle and almost imperceptible, but if there is a major shift in one of the three then that will precipitate a reevaluation of the other two.
Doing philosophy correctly can help uncover your own particular metaphysics, epistemology, and ethics. It can show how the particular implementations may be incompatible. For example, if you really believe that everyone is created by God (metaphysics), then that should determine how you treat them (ethics).
We may not realize it but our ethics (and by extension our metaphysics and epistemology) are revealed by our aesthetics. Think about what movies, TV shows, books, stories, blogs, or news articles you like to consume. The kinds of entertainment we like, or the fictional characters we identify with, act as a litmus test for our ethics.
What art is hanging on your wall? Is it realistic, like photographs, or hyper realistic paintings? Or is it abstract? What is the subject matter? All these things can reveal how you fundamentally view the world, and how you think about knowing the universe.
Just as asking about how one views consciousness will reveal their metaphysics, what one surrounds themselves with, or their aesthetics, reveals their ethics, and ethics is codependent on their metaphysics and epistemology.
*I stated that science does not have a preferred metaphysics. That is not entirely true. Because science, as an epistemology, requires a corresponding metaphysics and ethics. It's just that the metaphysical and ethical demands of pure science are minimal. Most pronouncements regarding what we "should do" because of science, actually have nothing to do with science as an epistemology. When people make an appeal to "Science", or Science™, they are always, without realizing it, bringing a particular metaphysics and ethics along with them. Their assertions don't actually have much to do with the epistemological method known as science.
