We cannot define all; IMO we have not a workable Definition of Art, and this in spite of "some meta activity that is closely related to 'philosophy proper'", i.e. Philosophy of Art.

In the same way, I think that is quite impossible to define Philosophy; but of course, we can describe it quite well. The main business of History of Philosophy is to describe it.

@MauroALLEGRANZA how can one describe a zero-sum equation without definitions? Would you simply say "there is nothing" or "it is equal"? but what then of all the detail and avenues of possibility, the life/process of the algorithm? You see I'm looking at what this (and your Art example) is telling us about our (as yet) inability to understand our own consciousness.

Philosophy is simply the seeking of answers to questions. Some of the bigger.. older questions are now best answered by science (natural philosophy).. but others are not accessible to scientific method.. What should I do with my life? What is the human condition and can we transcend it? It's tempting to think there are no questions left that can be answered just thinking about it.. but certainly it won't happen if people stop trying. Deep thinking is more important now than ever. Less smashing protons and more sitting deep in thought is what we need IMO.

@christo183 I think you're right. I think the problem is even more general. Our society tends to shun critical thinking generally. I know this is a divisive subject.. but I'm always amazed at the reaction one gets from intelligent.. STEM educated people when you ask what 'proof' there is that man landed on the moon in 1969.. rather than what 'evidence' there is. Its not about the event itself.. it's about discovering whether scientists on the whole are critical thinkers.. and sadly.. they are absolutely not.. at all. When did that happen, and what hope does that give us for the future?

IMO, the two "basic ingredients" of philosophy are : knowledge and wisdom. According to one of the leading tardition of Western philosophy, best exemplified by Aristotle, wisdom is achieved through knowledge. And this is the main reason why most of Western philosophy is linked with science. But there are other philosophical traditions (obviously mainly in the Est) where knowledge is not assumed as a prerequisite for wisdom.

@MauroALLEGRANZA I've always defined wisdom as the ability to choose, in the face of certain knowledge that no choice is entirely correct. Intelligence is the ability to recognised options, wisdom, the ability to choose one.

@MauroALLEGRANZA - i know of no tradition that seeks wisdom but not knowledge. The idea wouldn't make any sense. Perhaps you mean relative or worldly knowledge. All esoteric traditions seek knowledge and wisdom, It's what they're all about. The idea that one could have wisdom but not knowledge is very strange. Western philosophy has become closely linked to science precisely because it does not seek wisdom but is happy to potter around with mundane affairs. I see little interest in the pursuit of knowledge or wisdom in this tradition and this is what makes the question here rather tricky.

@PeterJ - Agreed ... But I like "mundane knowledge" and this is the reason why I'm interested in e.g. Aristotle and Wittgenstein and not e.g. in sufism and Jakob Böhme. Having said, taht, this is the reason of my first comment above: we cannot define art, philosophy, and many other human activities. But this does not mean that we cannot study and discuss and understand them.

@MauroALLEGRANZA - I'm not sure liking mundane knowledge means not liking any other kind but no matter. I'm not convinced there's any problem with defining philosophy or explaining it other than that there are various ways of doing it so don't have much to say. The OP seems to have defined it well enough to ask the question in the title.

@MauroALLEGRANZA I've always liked 'arcane knowledge'. But it's very difficult to come by sadly.

I think we reasonably describe English in English, since we describe the meta-languages we use to describe English in English... This part of your argument fails, no? It is just fine to address all of Philosophy in Philosophy. If we made a meta-Philosophy, it would be based in Philosophy the same way our meta-languages are defined in natural languages.

Sciences are not well defined, they are families of activities grouped together by vague resemblance, demarcating science and scientific method as a whole was not a success either, despite much effort. And one can easily describe a language without a separate meta-language, all natural languages are their own meta-languages, the separation between the two is an artifice introduced even into mathematics only in 1930-s, for technical reasons, and of little use elsewhere. There is no one "correct context" either, the more the merrier. The answer to your question is to discard most of its premises

@Conifold see edit. Also I would argue that formal langues in general exist to address inadequacies in natural language. Such inadequacies as may be responsible for, or a consequence of deeper issues, that would prohibit a sufficiently precise definition of philosophy.

In some ways, this is the barber paradox.‌​ As you alluded to, there's a well established school of thought that says that for any discipline X, establishing the borders and definitions for X requires a metalanguage for X, and is properly considered the domain of the philosophy of X, and NOT the domain of X. But what if X is itself philosophy? Does the barber shave himself? A lot of how we answer comes down to whether we think there's a good reason for a universal rule that a discipline cannot define itself, or whet

The technical reason is not precision but the need to avoid self-reference paradoxes, like the Liar, under the classical logic. One of the selling points of paraconsistent logics is that they can tolerate such paradoxes, and hence avoid the Tarski hierarchy of meta-languages, without any loss in precision. This said, precision is not always a virtue either, especially in philosophy, one of whose functions is to deal with the unsettled, and the unsettling. In short, part of philosophy's "definition" is that there is no point to defining it.

@ChrisSunami didn't think of that, see also discussion with Conifold about self-reference, and my question :philosophy.stackexchange.com/q/54384/33787

@Conifold As you note sciences aren't well defined either, but then why should they (as long as they work). Would there be a general rule for things that are pointless to define? Defining Philosophy still seems different... yet no less a fool's errand.

The problem is that good definitions only come at the end of inquiry, and sciences are more or less well-defined in areas where the inquiry more or less ended, established science. Philosophy's inquiries never end even locally, because when there is a prospect of establishing something it is moved out of philosophy, and when there is a crisis there, it is moved back in. It is the medium of reflection, the meta, the meta-meta..., and there is a branch of philosophy called metaphilosophy.