Quora Answer: If drugs can alter the way we perceive reality, how can we be sure that what we normally see is the absolute reality?

What we see  in normal everydayness is definitely not absolute reality in any sense. Normal perception is definite not it. But drug induced states are probably not it either. Meditation is probably the route to anything approaching it.

So this is a good departure point to talk about Being and Time by M. Heidegger which is a philosophical work in our tradition that touches on your question. He distinguishes the everydayness of the human self and its lostness in what is called Das Mann or the They which is everyday normal consensus reality. His book is about how one can individuate oneself from this consensus reality by thinking about death and becoming authentic. So for Heidegger you really only have to think about your own death to pull out of consensus reality and to see deeper into life and perhaps a greater reality.