I have long puzzled about why it is that materialists don't regard any inquiry that contradicts the idea that random assembly (with or without constraints) can account for all we observe as science.  As I continue to listen and read the objections offered it is becoming clearer. 

To a materialist, the purpose of scientific inquiry is to determine how things came to be within the framework of material mechanisms only.  Any inquiry into causation outside materialism is by default not scientific. Therefore the only valid modes of explanation available to scientists in their mind is necessity and chance or a combination of both.  Nothing else is allowed because by their definition, it cannot be science.

There are two very serious problems with this. 

The first is that there are many items and events in our natural world that contain characteristics that have never been shown capable of being generated by random and constrained chance processes.  Information is one of the best and easily identified examples.  The materialist has never been able to demonstrate that high levels of information can be generated by materialistic processes but the materialist assumes this is the case and instead looks for evidence to support the assumption. The materialist calls this pursuit of evidence in support of an assumption science.  Meanwhile discoveries that disconfirm the assumption are not treated as evidence.

The second problem is what happens if material processes is not the answer to items and events.  In this case the materialist will never discover the answer. 

Is the materialist suggesting that discovery of truth is not the purpose of science?  That instead the purpose of science is to confirm the philosophy of materialism?

That's exactly why Philosophy exists -to deal with questions whose answer can't be found through Science. Anyway, the good thing with science is that you don't need to do everything here and now. What today is a mistery may be resolved tomorrow. That we don't know today means that we must keep researching the material world for an answer, not that it's time to give up a material explanation.

Science is not ultimate, Science is not absolute, Science is not complete and Science is not infalible. BUT, it expands continuously and haves a incorporated correction device that makes it as perfect as we humanly can achieve to make it. Science is humble but developing. And it's the best tool we got to understand material reality.

(Some people claim that there is a reality beyond material reality. But then that's not Science but Philosophy, or maybe Theology)

So you are using subjective personal experience.  Thank you for the clarification.

Non material explanation is not Science.

Not correct. Intentional design follows known laws and yet design is not a materialistic process.  Deducing or inferring that something was designed is not a violation of any physical law or theorem.  This cannot be a valid reason to exclude design.  If something was designed then but we don't know how it was designed or by whom it was designed how is that any different than your appeal to unknown material laws?

tadpol, you'll have to come up with a better justification.

Science only concerns itself with things that can be tested. If it cannot be tested or exists beyond the realm of repeatable phenomenon, it is not science. Non-materialism cannot be tested, you should know this.

It's always equivication galore with you.

You are trying to understand design as if a material being did it, since you have no other reference point.
Plus, you say design is contingent and therefore not materialistic! Do you know of any other process that design, except your imaginary sky pappy? Materialists desing things all the time, and they do so for a materialistic purpose. You have abstracted the process into some Platonic form - no wonder you are a Theist!
Plus, you say you design something and test it.  You aren't testing to see if it was designed!  You are testing to see if it performs according to your design, and you have to know your purpose - you have to know the designers purpose in order to test if it is performing according to specifications.

Jeez, RF, you are really unravelling.

You are suggesting that this reply is disproof of materialism, because while my hands and computer follow known laws my mind does not?

The Pyramids are thought to be designed, and the study of them including inferences about their creator(s) is considered science. As long as evidence is the foundation of understanding.