> We can't "really" know anything about the "real" world either - yet hardly anyone takes solipsism seriously...
Philosophers generally take solipsism seriously. They just do something called "bracketing" regarding solipsism. "Bracketing" is a philosopher's way of saying, "Yes, this is a serious issue, but we can't make any progress unless we ignore the problem, so that's what we're going to do. But we'll be sure to keep it in the back of our heads as a possibility, lest it come back and bite us."
I.e., virtually every philosophical argument starts with an implicit, "For the sake of argument let's assume that solipsism isn't true." There are also probably dozens of other such worries that are typically bracketed.
Mathematicians often do something similar. There are certain mathematical conjectures (usually involving infinities in my experience) which we can prove can neither be proved nor disproved. So mathematicians will just assume some such conjectures for the sake of making progress. One example of this would be the axiom of choice.
Philosophers generally take solipsism seriously. They just do something called "bracketing" regarding solipsism. "Bracketing" is a philosopher's way of saying, "Yes, this is a serious issue, but we can't make any progress unless we ignore the problem, so that's what we're going to do. But we'll be sure to keep it in the back of our heads as a possibility, lest it come back and bite us."
I.e., virtually every philosophical argument starts with an implicit, "For the sake of argument let's assume that solipsism isn't true." There are also probably dozens of other such worries that are typically bracketed.
Mathematicians often do something similar. There are certain mathematical conjectures (usually involving infinities in my experience) which we can prove can neither be proved nor disproved. So mathematicians will just assume some such conjectures for the sake of making progress. One example of this would be the axiom of choice.