Seems there were these three professionals sitting around talking about the oldest profession (not THAT one!).

The Doctor says, "Well, the Bible says that God took a rib out of Adam to make woman. Since that clearly required surgery, then the oldest profession is surely medicine."

The Engineer shakes his head and replies, "No, no. The Bible also says that God created the world out of void and chaos. To do that, God must surely have been an engineer. Therefore, Engineering is the oldest profession."

The Lawyer smiles smugly and leans discreetly forward. "Ah," he says, "but who do you think created the Chaos?"