Imagine you and some friends are walking in the hills of South Dakota and you see some rock formations with four faces on it. At this point, you are all staring in awe and you say, "I wonder who carve these formations?" This prompts one friend saying, "Nobody carve them. That's just a natural occurrence over millions-no make that billions of years. The forces of nature – the wind, water and erosion – made those rocks appear to look like faces."
"You can't be serious," you reply. "There's no way those rocks look like real people by accident. The likeness is too specific and too complex, to have been formed by blind forces of nature. Some guy with a vision, some dynamite, and really big rock-cutting tools purposely made those rocks look like famous Americans." The point of the story is to lay out the design argument, traditional called the teleological argument. The key feature of this argument is: specificity, complexity, and purpose-descriptions normally assigned to an intelligent agent rather than a natural cause.