Ham often stresses a line of argument made within the broader creationist community, which resonates, at least somewhat, with the public at large. “There’s experimental or observational science, as we call it. That’s using the scientific method, observation, measurement, experiment, testing,” he said during the debate. “When we’re talking about origins, we’re talking about the past. We’re talking about our origins. You weren’t there, you can’t observe that…. When you’re talking about the past, we like to call that origins or historical science.” In other words, Ham was saying that there is a fundamental difference between what creationists call the “historical sciences”—areas of study, like astronomy, geology, and evolutionary biology, that give us information about the early Earth and the evolution of life—and other sciences, like physics and chemistry, which appear to be based on experiments done in the laboratory today.
On the surface, this does not seem completely unreasonable. There is, after all, a difference between an observation and an experiment. In the laboratory, one can have much better control when attempting to establish cause-and-effect relationships. However, to suggest that somehow this qualitative difference between observation and experiment translates into any sort of deep qualitative difference between the different sciences mentioned above is to demonstrate a fundamental misunderstanding of the nature of science itself.