Marcello notes how what we can understand about reality is limited by what we can observe and experience about the world.
It may be technically true that our instruments are limited and incapable of making certain measurements, thus limiting our direct understanding of reality, but it seems that Marcello also alludes to us being limited by a subjective perspective that is not fully possible to overcome.
This butts-up against our desire for ultimate truth, which extends from our need for understanding of our origins (As Marilynne notes, if we know our origins we feel that we will then be able to find our purpose in the universe or the meaning of our existence), but perhaps opens up a plurality of paths that may all lead to some understanding of the self and its place in the universe for the individual who chooses to pursue them.
Interestingly, Marilynne praises science for its capacity for self-criticism, yet there are truisms familiar to scientists that go along the line that science may only progress one funeral at a time. Science is a human endeavor, and the way in which new ideas are adopted can be a human and so chaotic process.
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