Originally posted by lucifershammer
If external reality is essentially un-knowable, then why do Kantians and Schopenaurians live as though it were? After all, what's the point in going to the supermarket to buy milk and eggs if you're not even sure you're actually consuming them when you think you do?
You're conflating different orders of "reality". There is empirical reality, logical reality, and philosophic (or spiritual) reality.
Empirical reality is concerned with external reality (from subatomic particle, to galaxy). Part of empirical reality in the human context is the functioning of the body. The body needs food to eat, therefore we eat.
Logical reality is concerned with simple conceptual entities. One plus one = two. Total = All. Nothing = absence of anything. Etc.
Philosophic or spiritual reality is concerned with matters of deeper realization via the cultivation of
insight. The point behind Kant's reasoning (in the context cited above) is that bodily senses filter our experience of external reality, thus rendering external reality unknowable in any ultimate sense
via the body and its sensory input -- as it is our senses that inform us about the
external universe.
Example -- light takes about 8 minutes to travel from the Sun to Earth. Therefore, when you look at a nice sunset, the Sun that you are seeing is not the Sun of present time reality. You are seeing the Sun as it appeared eight minutes in the past.
Example -- A human, cat, and fruitfly all look at an apple. Each has completely different optic capacities. Therefore, all three will see something completely different. Which one sees the "real" apple -- the human, cat, or fruitfly? Ditto for auditory capacity, touch, smell, etc.
Example -- The electromagnetic spectrum has one small portion that the human eye can properly process, called the "visible light" portion. We can't see X-ray, infrared, ultraviolet, radio waves, gamma waves, etc. And yet they are there. An entity that could see X-rays (for example) would see something completely different. We only perceive a tiny portion of the universe's energetic manifestations. Does that mean the rest of its manifestations are not there?
Therefore, if you hold to God as an external entity in space and time, you can never fully hope to perceive him directly via this limited human form, and subsequently "know" his ultimate nature and capacities, including so-called powers. This is why spiritual/philosophic reality is concerned with
insight, not external reality. But developing insight doesn't mean you stop buying milk or eggs.
As the old Zen expression has it --
Before enlightenment, chop wood, carry water from the well.
After enlightenment, chop wood, carry water from the well.
Or as Christ put it, "render unto Caeser what is Caeser's, and to God what is God's." So developing spiritual insight doesn't mean we stop functioning in the world -- including paying taxes on the eggs we buy. It means rather we learn to recognize the inherent limitations of "knowing" external reality, and thus by extension, any external God.