> You seem to be suggesting that humans are capable of perceive objective truth for non trivial things.

I believe that for situations where a single human has enough information and ability to ascertain the truth, most humans deliberately will not make a beeline for the truth. They sort of veer off to the side towards a half truth that better suits their situation. None of this is a conscious choice though.

Self deception is completely orthogonal to our ability to ascertain the actual truth. As I said even if we were magically gifted this ability, most choose not to use that ability.

Of course this quality lives on a gradient, some people are really good at self deception, others are really bad at it.