Defending Philosophy

On days when I am not masquerading as a theologian, I spend time encouraging people to tackle philosophical issues. Contrary to popular opinion, philosophy does not deal entirely with the existence of nothing or "can God make a stone so heavy he cannot lift it?" or even "what is a chair?" Philosophy, similar to other disciplines, finds its definition to be very muddy, while at the same time, philosophy is a vital discipline that would cause the demise of most all other disciplines should it collapse.
Philosophy seeks to understand the underlying structures that compose both itself and other disciplines. How one answers certain philosophical questions will determine how one will answer other questions in a discipline (at least, if one desires to be consistent in thinking, which is a thought built upon the law of non-contradiction). For example, in answering the question, "What is ultimate reality composed of?" if one should choose to answer "merely material," then one precludes any immaterial concepts into the discussion. Thus, things like God, angels, and ideas cannot even be considered as real things.
Some people follow Kant's conclusion, that faith and reason (and by extension, philosophy) are in separate, non-overlapping spheres. Thus, some advocate that the Bible alone is sufficient. These individuals would refer to the admonition not to fall into vain philosophy. Others take the opposite position that faith bears no relevance in the search for truth. The robust Christian worldview sees faith and reason as extensions of a unified whole.
Yes, philosophy does examine questions about knowledge, ethics, identity, but these are not superfluous endeavors. Understanding identity helps people to understand how a person remains the same thing over time (whatever that means). To elaborate a touch further, suppose that materialism is true, so that all that is real is and only is material. On this premise, one should be lead to the conclusion that a thing is the composition of its parts. Therefore, any loss of a part means the thing is no longer the same thing. It is not identical with what it once was (in a non-technical manner of speaking). If you lose a cell, you have ceased to be and something else stands where you once stood. To continue the thought, most all of your cells are replaced over the years. Thus, whoever stole the cookie from the jar, that could not be you, because you are not composed of the exact identical parts that composed the six-year-old boy (unless you are just now a six-year-old boy with his hand in the cookie jar, which could still be argued that you are not the same person as the thief). Accountability becomes a mushy concept to enforce. Not that that in and of itself disqualifies physicalism from being true, but the experiment helps to show that clarification is needed on the matters, especially when the entailment of our beliefs run contrary to our intuitions (at which point here, I will defer to my good friend, Randy Everist, who is fascinated with intuition and has several good articles on the matter http://www.randyeverist.com/2011/04/argument-for-intuition.html ).
As frustrating as it can be, I enjoy philosophy because it forces one to focus on the vital points. That said, I still scratch my head over the Ship of Theseus. The only comfort I have after thinking on Theseus's ship is that I find it disanalogous to people in that people are not merely physical and that the immaterial aspect preserves their identities.