There are two pieces of evidence which allow me to hypothesize the existence of an objective reality from within my subjective experience:
1. My subjective experience makes predictions which are wrong within my subjective experience in ways which my subjective experience does not explain. Or put another way, I experience cognitive dissonance.
2. When I attempt to align my subjective experience with a hypothetical objective reality (that is, when I attempt to learn) the predictions made from my subjective experience are wrong less frequently. Or put another way, learning decreases cognitive dissonance.
Of course, these subjective experiences could be explained by a self-flagellating subjective experience that inflicts me with cognitive dissonance and then rewards me for attempting to align my subjective experience with a nonexistent objective reality. But that is (subjectively!) too convoluted an explanation to be satisfactory.
1. My subjective experience makes predictions which are wrong within my subjective experience in ways which my subjective experience does not explain. Or put another way, I experience cognitive dissonance.
2. When I attempt to align my subjective experience with a hypothetical objective reality (that is, when I attempt to learn) the predictions made from my subjective experience are wrong less frequently. Or put another way, learning decreases cognitive dissonance.
Of course, these subjective experiences could be explained by a self-flagellating subjective experience that inflicts me with cognitive dissonance and then rewards me for attempting to align my subjective experience with a nonexistent objective reality. But that is (subjectively!) too convoluted an explanation to be satisfactory.