Empiricist
One that believes experience, especially of the senses, is the only source of knowledge.
An Empiricist is a philosopher or a sage. A person with great knowledge.
Conspiracy Empiricists
One who propagates an idea or ideas that many important political events or economic and social trends are the products of deceptive plots that are largely unknown to the general public; via practical experience and experiments as a basis for such idea they are propagating.
Conspiracy empiricists often think just because a dominant theory is mostly sufficient for explaining most of a phenomena doesn't mean one shouldn't attempt to teak the theory via experiments to find more information.