the ethernal problem, how can we prove our mind is making real assertions about the cosmos? is our mind capable to really perceive "reality"? how far can we really know? is math capable of serving us to solve this issue? but then math comes from the human mind and so we go "in circulus ad infinitum"...
as it is one of the best answers, basically a "summary of philosophy" it comes from john 1.1 "in the beggining was the logos/logic...and everything was made by this logic"...
this offers 2 conclusions:
1 yes our mind is "trustworthy" , our minds can really make good assertions about the universe because we have logos (logic, conciousness) the universe and us are in a feedback loop in logos(in logic) , "ego cogito ergo sum"(Descartes 1637)
2 no, we are not goin to know everything with all the details about the universe because we are not the creators of it. "verum ipsum factum" (Vico 1710) meaning that only the creator can know all details about his creation, a third person/observer can only aproximate or grasp aspects of it but not everything in full detail. (as it is quantum mechanics is confirming this situation)
for example if we are a simulation only the programer will know the "real reality" of his creation....in what chip we are running in, in what language is our program, what is the reason for this simulation, what is the final objetive to create it, what is the intention...
