As described brilliantly by Neil Degrasse Tyson at the Beyond Belief 2006 Conference, many scholars of the past have attributed complexities of the universe that they could not explain to an Intelligent Designer. Even Isaac Newton - yes THE Isaac Newton, fell back on a divine architect when he was unable to invent the differential calculus required to calculate gravititc influences on the perturbations of the planets he could observe in our own solar system.
We read some very pithy comments about Intelligent Design - or rather on how the minds of proponents of Intelligent Design function. It is possible that these visionaries reach a limit to their understanding, a demarkation, if you will, between what they can imagine and what they observe. ID Proponents who use the structure of the human eye as an argument against evolution, and an argument for a hidden architect simply cannot imagine a natural selection process that could result, over time, in a structure as complex as the human eye. Thus stumped by their inability to concieve of that process, the fall back to the "architectural default position" that there was a designer who made it that way.
What often gets overlooked is that these statements of belief about a hidden architect function solely as a personal decision to believe, rather than a universal norm for the conclusion. They may find many people of faith who are prone to be sympathetic to the idea of a hidden architect (read: god) simply because their faith based structure allows them to absorb the idea of "Hidden Architect" into their notion of "Divine Creator".
What this shift of opinion does, however, is simply close a perceptual door on further research or thought.
Now it is possible that the person who comes to believe in a hidden architect may have reached the edge of their ability. They have come so far, but simply cannot go farther due to lack of training, ability or even techniques or knowledge not providing the skills or knowledge they need to step further (as in Newton's inability to plot the gravitational forces affecting the planets because he lacked the differential calculus required to make the mathematics possible).
I think the question I have about this whole process is where does the ability to come to create such a "thought terminating" conclusion, and then simply partition off any further questions about the process/object/research at hand?
Tyson's Speech at Beyond Belief: http://beyondbelief2006.org/Watch/watch.php?Video=Session%202