Philosophy is also a word and a marker. It makes it possible to contrapose it to other words, like science, as it was done in this thread already. Ultimately these attempts at categorization are extremely weak in the face of what people do every day. Scientists do metaphysics all the time, have to revel in the wildest fictions as a matter of course, while philosophers are bound by their evidence and constrained to remain quiet without observation. The distinctions are political and internal to historical formations. Those that argue for their purity are often blinded by words and the belief that there are underlying "logics" to any academic discipline. Many locked threads in this forum are due more to someone having internalized certain origin myths about how science|philosophy relate, than the conversation becoming different in kind from any other conversation on these forums. Having the forum here to me seems like a symptom of scientists wishing to keep living in a kind of split-personality mode. To speak philosophically =/= to speak scientifically, so you have to go here. The kind of sense it makes is internal to certain scientistic discourses, the reasons for the partition will be sought in rules of method, conceptions of what reality itself is, traditions and so on. Philosophy will be done to tell you why philosophy has to remain external to "science". It's a very queer and mangled worldview, but consequential.