To paraphrase ... science doesn't evolve by providing answers, it evolves by replacing old questions with better new ones (notice better, new by itself doesn't count for much). The evolution of these questions are guided by empirical and quantifiable evidence. Though there is a dialectic between what is measured and what is theorized. With "voltage" for instance, it came about as the solution to a chicken/egg problem. Before Volta, nobody knew there was a voltage to be measured. Once they realized there could be, and they measured it, then they knew they knew something.