Now we are getting the crux of the matter. What did the gurus believe about knowledge? Great inquiry!
As for 4 kinds of truth.
Deductive or logical
Formal or mathematical
Empirical or inductive
Religious based on a priori assumptions (beliefs) about good, evil and the supernatural.
Slight addition. Is Sikhism really a priori assumption~: May be or may be not as it is beyond reasoning. May be it is not an empiricist based study as well but is not a radicalism leading to some thing that senses can make us know the truth based on the perceptions of senses. Something is missing.
Carry on; shall peep into from time to time.
E & OE