How about this... a few years ago, people believed the celocamph to be exinct. We now know that not to be true. We also just found a new species of whale, this very year. PArticle physics has new avenues, as have the majority of the sciences. SARS was an unknown illness until earlier this year, and the dynamics behind its transmittal are still largely unknown. The genetic code has been cracked, but we are still ignorant on exactly how it works, and the list goes on and on. New discoveries are made which brings them into the realm of the "defined" but there are things which we still do not know, and lie within the realm of theory... a good and easy example is a black hole, which when crossing the event horizon, gravity takes down light and and matter into the singularity, and if a person was to get pulled in, that person would be ripped apart until finally the very atoms would be left, and those would be pulled apart. Now I ask you this, just how do we know that? The answer is that we don't. We are going by obsarvation and patterns. This is exactly the same process that was used when Qi was first defined. Bio-electric energy does exist; however, I doubt, seriously doubt, anything like what the ancients proposed exists. Qi means both air and energy, and we know that both of these exist. Further, we know that energy can neither be created nor destroyed; however, it does change phase. BUT when this was first proposed, it would have been considered foolish, and depending on the era, witchcraft. Today we have evidence to suggest that acupuncture works, to varying degrees. And yet, this is a practice which evidence leads us to think was practice by the "iceman" (due to tattoos which correspond to acupoints) who lived just a few years before us. (lol).
Before one can just discount anything, it should be analyzed thoroughly and investigated. Even scientific law is changed when new discoveries make that a necessity.