A Question about Naturalism and Empiricism

Today we begin an on-line discussion with co-blogger, Scott Hatfield at http://monkeytrials.blogspot.com/. We begin with a question that concerns those in positions of professional science, and also those not in such positions. My thought is that we might pursue such issues into the no-no zone: transcendence, in order to determine if there is any rational path into zones of no physical presence. First I will post, and then Scott will take it and post, then I will....you get the picture.

The first question is as follows:

"Is there anything that compels a working scientist (who tends to function, albeit not exclusively, as an empiricist) into adopting either naturalism or materialism as a private matter?"

My take on this is twofold: First, depending upon your definition of Natualism and Materialism, a working scientist has to believe that for each physical effect there exists a physical cause that is measurable and repeatable per the rules of empiricism, otherwise the efforts toward empirical resolution would be futile. From what I have seen, both Materialism and Naturalism require that causes exist in physical space-time. A typical definition is as follows:

Epistemological Naturalism(Part 3): Things not located in space or time cannot enter into causal relationships.
Evan Fales, Naturalism and Physicalism, The Cambridge Companion to ATHEISM, 2007, pg126.

This does not define away things not located in space-time, as does a more critical Materialism definition. It does require physical effects to have physical causes.

Second: Now if self-experienced or introspective "things" do occur, they would exist outside the realm of empiricism, and they must have a different kind of evidence to support the knowledge of their existence: physical knowledge under empiricism will not do, it cannot do the job. This type of existence, and causal relationship is not denied under Naturalism [Note 1 below] but is denied under physicalism / Naturalism. The question then reduces to the type of evidence that we might allow to be valid when approaching apparently transcendent "things". (Transcendence being the state of existence outside the range of physical empirical existence and causality).

A second question for discussion is as follows:

"Is there any reason for a working scientist to deny (not to recognize) the non-empirical basis for empiricism itself?

An example is the First Principles, ontological, that are required in order to halt the necessity of an infinite regression of validation of sub-levels of the postulates or premises. Other examples are the universals, numbers, sets, math, logic, and the rational persistent immutable physical laws across the universe, etc that are presumed true / valid, without hope of empirical proof of the reason for their existence.

At this point I turn it over to Scott for discussion and other ways of looking at this.

[Note 1: Correction: not denied under empiricism][1/10/08]