In the 19th century the anatomy of the eye was known in great detail and the sophisticated mechanisms it employs to deliver an accurate picture of the outside world astounded everyone who was familiar with them.

We are not inferring design to account for a black box, but to account for an open box.

Biology has progressed tremendously due to the model that Darwin put forth. But the black boxes Darwin accepted are now being opened, and our view of the world is again being shaken.

I find the idea of common descent (that all organisms share a common ancestor) fairly convincing, and have no particular reason to doubt it.

The question is: exactly how did life get here? Was it by natural selection and random mutation or was it by something else? Everybody - even Richard Dawkins - sees design in biology. You see this design when you see co-ordinated parts coming together to perform a function - like in a hand. And so it's the appearance of design that everybody's trying to explain. So that if Darwin's theory doesn't explain it we're left with no other explanation than maybe it really was designed. That's essentially the design argument.

The trap does not work until all the parts were there. The system itself doesn't work until you fit all of them together.

Although Darwin was able to persuade much of the world that a modern eye could be produced gradually from a much simpler structure, he did not even attempt to explain how the simple light sensitive spot that was his starting point actually worked.