Complex sentence: He was also considered a strict empiricist who threw out the idea that knowledge could be obtained by means other than descriptions of facts those that believed this thought that revelation or mysticism could not be sources for obtaining truth.
Split into simpler sentences: He was also considered a strict empiricist who threw out the idea that knowledge could be obtained by means other than descriptions of facts. Those that believed this thought that revelation or mysticism could not be sources for obtaining truth.