The chapter is called "The Origin of Science and the Possibility of Design." It's short, unimportant and uninteresting. Its purposes, along with Chapter 7, are twofold: 1) to counter the claim that ID theory is "not science" and 2) to establish that "historical science" (that which deals with the past) is not all that different from "operations science" (as defined by Charles Thaxton and others), specifically because the theorizing of "historical science" can be considered testable.
Comments in non-random order.
I was not an experimentalist, but a former applied scientist and philosopher of science. In my investigations of the DNA enigma, I began to marshal every relevant intellectual resource and insight – scientific, historical, mathematical and philosophical – that I could.
I remembered that my Dallas mentor, Charles Thaxton, thought that many scientists today rejected design out of hand because they failed to recognize that there were different types of scientific inquiry, specifically, that there was a distinctive kind of scientific inquiry concerned with investigating and explaining the past. His distinction between origins and operations science suggested a reason to consider an "intelligent cause" as a possible scientific explanation for the origin of life.
According to this view it may be inferred that all vertebrate animals with true lungs are descended by ordinary generation from an ancient and unknown prototype, which was furnished with a floating apparatus or swimbladder. We can thus, as I infer from Owen's interesting description of these parts, understand the strange fact that every particle of food and drink which we swallow has to pass over the orifice of the trachea, with some risk of falling into the lungs, notwithstanding the beautiful contrivance by which the glottis is closed. In the higher Vertebrate the branchiæ have wholly disappeared—but in the embryo the slits on the sides of the neck and the loop-like course of the arteries still mark their former position. But it is conceivable that the now utterly lost branchiæ might have been gradually worked in by natural selection for some distinct purpose: for instance, Landois has shown that the wings of insects are developed from the tracheæ; it is therefore highly probable that in this great class organs which once served for respiration have been actually converted into organs for flight.