I come back to FG, because I think he is seriously trying to engage with ID, and I am very pleased to report that he is making significant progress.
In my post “Who Designed the Designer Argument Demolished in Three Easy Steps” I demonstrated that the infinite regress argument has no real force by giving what FG called a “concrete example” of how a design inference can be valid in the complete absence of any knowledge of who the designer was or where he/she came from.
FG writes. “When applied to a single concrete example like the one you gave, your inference could be valid . . .”
FG then slips when he says: “The infinite regress problem is real and does defeat ID the moment your argument is invoked to explain first life.”
Not so. ID posits the following: CSI and IC have never been directly observed to have arisen though chance or mechanical necessity or a combination of the two. Conversely, CSI and IC are routinely observed to have been produced by intelligent agents. Moreover, intelligent agents leave behind indicia of their acts that can be objectively discerned. Therefore, using abductive reasoning, the best explanation for CSI and IC is “act of intelligent agent.”
How does this apply to first life? (By “first life” I presume FG means “first life on earth.”) Well, we cannot directly examine first life to determine whether it exhibited CSI and IC. We can only observe existing life, and when we do we find that even the most simple extant life forms are staggeringly complex. From this observation we infer that the first life on earth also exhibited CSI and IC. (To be sure, some would attempt to deny that first life is complex, but given the unanimous verdict to the contrary of all of our observations simple logic suggests that the burden is on those who make such a suggestion to demonstrate its plausibility.)
We cannot know for certain whether first life exhibited CSI and IC. ID merely says that if it did, the best explanation for the existence of the CSI and IC in first life is best explained by “act of intelligent agent.”
This is where FG goes off the rails. He/she asks “But who designed first life? By definition first life could not have been designed by a living being.” The answer is, as I have said many times before, ID does not examine the question “What is the source of all design?” ID examines the question “Is this particular thing designed?” And it says of the particular thing “first life on earth” that if it exhibited CSI and IC the best explanation for the existence of that CSI and IC is “act of intelligent agent.” A physicist (when he is doing physics) does not ask, “Why is there something instead of nothing?” Similarly, an ID proponent (when he is doing science) does not ask, “What is the ultimate source of all CSI and IC?”
Why is this? Because questions like “Why is there something instead of nothing?” and “What is the ultimate source of all CSI and IC?” are simply not subject to scientific investigation. This does not mean that grand metaphysical or philosophical questions like these are uninteresting. They are very interesting (even vitally important). Nevertheless, the answer to these questions cannot be investigated by scientific means.
Wittgenstein famously wrote: “Whereof one cannot speak, thereof one must be silent.” As a scientist a physicist cannot speak to the question “Why is there something instead of nothing?” Therefore, he must remain silent on that question. As a scientist an ID proponent cannot speak to the question “What is the ultimate source of all CSI and IC?” Therefore, he must remain silent on that question.
Therefore, to FG I say, many ID proponents have a view of the source of all CSI and IC. But those views are of the “metaphysical, philosophical and religious” sort. They are not scientific views and for that reason are not subject to scientific investigation. However, with respect to any particular, as you say, “concrete example” of CSI and IC, ID proponents argue that the best explanation for its existence is “act of intelligent agent.”