This “common sense” argument is pretty selective. Let’s look at what else common sense tells us. And let’s, for the moment, just look at individual organisms and leave evolution aside.
If an alien spacecraft crashed on Earth, and you were looking at the wreckage, you’d probably be able to tell what parts were the alien’s bodies, and which were it’s machines. Common sense is enough to know the difference between mechanical devices, and biology.
It’s more than just form. Mechanical devices have to be constructed piece by piece, with each individual part placed deliberately - it requires an act of consciousness. Biology, on the other hand, doesn’t. I’m sure you accept the science that shows us in excruciating detail how nearly every part of an organism grows into its final form, without conscious intervention. Further, I’m pretty sure you accept the science that shows us that it all grows from DNA in some form, that the DNA directs automatic chemical and physical processes that create each of the structures of the final organism. If you don’t accept at least that much, there’s really no point arguing any further.
So we’re down to the level of the DNA, the code that contains all the information needed to construct an organism, but does not itself contain anything in the final form of those structures.
Common sense, then, shows you the difference between a conciously constructed mechanical device and a bilogical organism. It shows you that consciousness is needed in every step of production of a mechanical device (modern automation notwithstanding - it doesn’t change the argument, it only obscures the common-sense conclusions), and that biological organisms grow without conscious intervention, at least from the point where the DNA exists. And common sense lets you see the difference, including the difference in the method of construction between an electric motor with a propeller and that of a bacterial flagellum.
So the only real question left is how the DNA, the code for creating the organism, is created. One of the questions is: can the code change without conscious intervention? There are common concrete demonstrations, both indirect and direct, that show that it can. Indirect proof comes in the form of computer code. Of course, computers and the code that run on them are consciously created. But it is easily demonstrable that the code can be created in such a way that it responds to its “environment” and changes itself in ways that are never intended by the person creating the original code - in ways that do not require conscious intervention.
The more direct proof is found all over genetic science. We have seen untold instances of organisms that change in response to their environment in ways that provide them an increased ability to survive in that environment. And we’ve seen directly that such a change in the DNA, including when it has been changed directly through genetic engineering, results in changes to the form, cellular chemical processes, and behavior of the organism.
So we see, by common sense, that the DNA code can change without conscious intervention. We’re at what the creationists distinguish as “microevolution”, the modification of an already existing genome. The evidence that this does indeed occur is so strong as to be reasonably considered irrefutable.
So we’re left with the creation of the DNA itself, and the addition of new pieces of code to it. The latter is not difficult to imagine happening, although there is not nearly such solid demonstrations of it available yet. Even so, this is the realm where common sense does not provide as much help. But it is the last part of the chain in which common sense does not help. Everything after this, from modification of DNA to the construction of biological stuctures all happening without conscious intervention is just as much a matter of common sense as the fact that a mechanical device was created by conscious deliberation.
The idea that common sense should treat the observation of an unknown mechanical device the same way it treats the observation of an unknown biological structure, and that it demands that we come to the same conclusions about how each came to be in the form we observe it in, is comically naive, and need not be taken seriously by anyone.
That one is getting so overused and worn out that I cannot treat it as anything but a deliberate lie. You know as well as I do that evolution theory does not rely on chance alone. The fact that creationists still trot it out as a rhetorical ploy every chance they get is proof of their inherent dishonesty… unless it’s proof of a cognitive disability so severe it borders on mental retardation. Take your pick which way you prefer me to think of you.