Because God. There is no excuse apart from origin, and our self-awareness compels us to attempt to explore it.

our self-awareness compels us to attempt to explore it — whollyrolling

Why?

I think that both metaphysics and epistemology are impossible to avoid if one is doing philosophy. All that's required for each is to at all wonder about and address, in some manner, (1) what sort of stuff there is/what it's like/what its relation is to other stuff, and (2) what we can know/how we can know it . . . not necessarily in that order.

A long-standing assumption in philosophy is that there is a need for metaphysics. — frank

Challenging this very assumption was the modern school of positivism:

The attitude of Vienna Circle towards metaphysics is well expressed by Carnap in the article 'The Elimination of Metaphysics Through Logical Analysis of Language'. A language, says Carnap, consists of a vocabulary, i.e., a set of meaningful words, and a syntax, i.e., a set of rules governing the formation of sentences from the words of the vocabulary. Pseudo-statements, i.e., sequences of words that at first sight resemble statements but in reality have no meaning, are formed in two ways: either meaningless words occur in them, or they are formed in an invalid syntactical way. According to Carnap, pseudo-statements of both kinds occur in metaphysics.'
...

According to Carnap, although metaphysics has no theoretical content, it does have content: metaphysical pseudo-statements express the attitude of a person towards life, and this is the role of metaphysics. He compares it to an art like lyrical poetry; the metaphysician works with the medium of the theoretical; he confuses art with science, attitude towards life with knowledge, and thus produces an unsatisfactory and inadequate work. "Metaphysicians are musicians without musical ability". — Wikipedia

Positivism was enthusiastically advocated by A J ('Freddie') Ayer:

Ayer achieved great success with his first book Language, Truth and Logic (1936). Written with verve and enthusiasm, it gave a clear statement of Logical Positivism. This doctrine maintained that there are only two ways in which one can make meaningful statements: first by making statements which can be verified by observation; second, by making ones which are true in virtue of the rules of language. Anything else is meaningless. In particular, the idea that philosophy is a search for first principles was “a superstition from which we are freed by the abandonment of metaphysics.”

Now, I can think of a whole set of questions which pose a challenge to positivism, without any reference to 'God'.

The first is: what is the ontological status of number? Is it an artefact of human thought, or are the real numbers real in any possible universe, independently of any particular mind? And if they are real, in what sense is that so? And what is the ontological status of natural laws? Are they too likely to be invariant in any possible world, or are there other worlds in which F does not equal MA? Are natural laws self-explanatory and foundational, or can they be resolved to underlying, deeper laws? And why is nature law-like in the first place?

These questions are not posed to elicit an answer, as they're unanswerable (i.e. you might think you have an answer, but there is no consensus on them amongst philosophers and scientists, so whatever answer you think you have will be contested). Both questions are fundamental to the doings of science, yet neither are directly reducible to either empirical or analytic propositions.

Hence, metaphysics lives. It simply changes clothes from time to time.

Expressing the matter as a need is metaphysical in so far as the question recognizes that there are agents and they want to understand what the hell is going on.

Why never has a reasonable answer.

think that both metaphysics and epistemology are impossible to avoid if one is doing philosophy. — Terrapin Station

I agree. Even if one turns against transcendental philosophy and becomes a hardcore anti-realist, the journey to that position requires some immersion in metaphysics.

But why even start that journey? Is it psychological?

These questions are not posed to elicit an answer, as they're unanswerable — Wayfarer

You're saying that ontological statements aren't truth-apt? Is that right?

Expressing the matter as a need is metaphysical in so far as the question recognizes that there are agents and they want to understand what the hell is going on. — Valentinus

So posing that there are agents is a metaphysical activity? Why so?

Why never has a reasonable answer. — whollyrolling

I think it does sometimes.

You're saying that ontological statements aren't truth-apt? Is that right? — frank

No, I'm saying that they can't be answered - well, they can't be answered unequivocally. They're in some sense beyond adjudication, you can't appeal an ultimate authority to judge the different responses. So they really are metaphysical questions. (I believe there are more and less appropriate metaphysical views, but by their nature, they are not subject to ordinary validation.)

The problem is that I think the positivist attitude really doesn't take into account the possibility that knowledge, even that gained by way of science, is limited in some fundamental respect. It wants to declare that the world known to the sciences is the only real or at least meaningful world. In that sense, positivism is simply the most consistent expression of that aspect of the so-called Enlightenment, which sought to replace metaphysics with science.

No, I'm saying that they can't be answered - well, they can't be answered unequivocally. They're in some sense beyond adjudication, you can't appeal an ultimate authority to judge the different responses. So they really are metaphysical questions. (I believe there are more and less appropriate metaphysical views, but by their nature, they are not subject to ordinary validation.) — Wayfarer

I think this is a pretty good description of ontological anti-realism. How did you arrive at this view? Did you start out with devotion to some theory and then eventually give up due to lack of verifiability?

How one 'arrives at' such a view is typically mysterious and often sudden, in my experience. It's something like a gestalt shift, an 'aha' experience.

I don't think anyone who's genuinely looking for an answer ends where they thought they would.

As Kant pointed out we have an unavoidable tendency to wonder and speculate about the "ultimate" nature of things. We cannot achieve any such knowledge via empirical inquiry or pure reason. Diverse metaphysical ideas might entail different ethical stances, so metaphysics may of practical significance.

Another important question is as to whether metaphysical attitudes or dispositions can be coherently argued for, or whether they are more suitably seen as being based on intuition and experience. The point is that my experience or intuition is only a good reason (if it is a good reason) for my own metaphysical attitude or disposition, and convincing others would be more a matter of rhetoric than of rigorous argument.

Having said that, if you are convinced to adopt my metaphysical attitudes or dispositions it will hopefully be on the strength of your own intuitions and experiences, and not because I am charismatic, or because you have a tendency to blindly follow others.

So what you're saying is that Kant was living in a fantasy? Oh, and that you are as well?

What makes you think I said that?

We cannot achieve any such knowledge via empirical inquiry or pure reason. — Janus

This.

How would we be able to achieve metaphysical knowledge by those means? The very idea of metaphysics is that, as a domain of enquiry, it is not within the domain of physical, i.e. emprical, enquiry. And pure reason alone cannot tell us anything about anything.

Metaphysics tries to understand the physical by applying the idiotic to it. The final outcome of empiricism is some possible understanding of things, while metaphysics is as futile as anarchism.

"Pure reason" is an empty fist flaunted at unanswerable questions.

The final outcome of empiricism is some possible understanding of things — whollyrolling

Actually, you are wrong. The final outcome of empiricism is absolute doubt or solipsism.

Actually, you are wrong, the final outcome of empiricism is some possible understanding of things, as I just said earlier.

Everything that has been determined about our surroundings has been through empiricism. Please feel free to explain what philosophy has done for humanity apart from its isolation of wealth as the epitome of knowledge.

Metaphysics tries to understand the physical by applying the idiotic to it. The final outcome of empiricism is some possible understanding of things, metaphysics is as futile as anarchism. — whollyrolling

I have no doubt you have plenty of other groundless pronouncements to make, too; but save your breath, I'm not buying.

Actually, you are wrong. The final outcome of empiricism is absolute doubt or solipsism. — Merkwurdichliebe

Yes, a key point that is often ignored or glossed over by empiricists is that they are basing their positivism regarding the metaphysical provenance of science on nothing more than personal preference for a mechanistic worldview; and if they rightly try to eliminate the latter, they will indeed be left with, as you say, "absolute doubt or solipsism", since there is no way to get from an empirically eliminativist paradigm to the fullness of human experience.

To call something groundless, you have to first take the ground from beneath it, Do your worst. You haven't said anything yet.

No, I call a claim groundless when no ground has been proposed. First you'll have to provide some purported ground before I can show you that it fails to support what you think it does.

As Kant pointed out we have an unavoidable tendency to wonder and speculate about the "ultimate" nature of things. — Janus

When I said this I should have added the qualification that I was referring only to those of us who have sufficient imagination.

How about skyscrapers, bridges, medicine, space travel, psychotherapy, economics, popular music, transcendental meditation, professional sports, agriculture and evolution, just to start this somewhere. Tell me, what has metaphysics done to benefit humankind apart from handing its mistakes over for real intellects to resolve?

Where have I said that science does not have any practical applications? And where have I spoken about metaphysics being of any "benefit" to humankind? You made the groundless claim that empirical knowledge gives us metaphysical knowledge. Care to offer some support for that contention, instead of presenting lists of artifacts and activities that science may or may not be thought to have significantly contributed to?

Nowhere did I say that metaphysics provides knowledge, and you can't pretend that any of the things I've listed did not come from empirical research and development. Now you're beating around the bush because you have no legs to stand on.

We cannot achieve any such knowledge via empirical inquiry or pure reason. — Janus

The point is that my experience or intuition is only a good reason (if it is a good reason) for my own metaphysical attitude or disposition, and convincing others would be more a matter of rhetoric than of rigorous argument. — Janus

Maybe you can stand on your own two metaphysical legs and tell me specifically what you're not buying. Tell me I'm not standing on solid ground while you say nothing about anything.

It would follow suit, given a praise of any kind of philosophy, that someone would defy science--science is the death of reason. Something more powerful than reason has come to the surface, and philosophy hates it for exposing the method behind all the little slight-of-philosophical-hand tricks.

Chimps, horses and cats all have experience. Why didn't they invent science?

Are you aware of them being self-aware?

How can you possibly equate experience of any indeterminate kind with an aptitude for science based on an awareness of self?

What does that have to do with it? The question is, if 'experience' is the sin qua non, the magic ingredient from which, as you say, all science is derived, then why are not animals capable of it? They have experiences as surely as do humans.