The way I see it, the core of philosophy is the hard problem of consciousness. Once you understand that, there's not much left. Some people include aesthetics or ethics in philosophy, but that's really just psychology, biology, maybe sociology.
I can see how aesthetics can be reduced to biology, but I don't think ethics reduces so cleanly. The fields you mentioned are all about what "is" while ethics is about what "ought" to be, and there isn't a clear path from one to the other.
You might not be inclined to explore philosophy, but David Hume pretty much took the field to its logical conclusion, so it's worth studying him. His philosophy was pure and rooted in first principles. Most of philosophy after Hume is tainted by the assumption of premises not derived from first principles.
