Divine Revelation (Revelation from God is the primary and/or only way of gaining true and certain knowledge)
Rationalist/Platonist (The world experienced by our senses is illusory, but we can gain true knowledge of reality through innate logical ideas in the mind)
Positivist (We can gain certain knowledge of the universe, but only through the empirical sciences and mathematics, i.e. only scientific knowledge counts as knowledge)
Non-Positivistic Empiricist (all of our knowledge is gained through sense experience, but this can include religious/moral/asthetic experience in addition to basic facts gained by empirical observation)
Moderately skeptical (we can have some probable knowledge of the universe, but no certitude)
Complete skeptic (we have no real knowledge of anything)