"I can understand your point that , in the absolute , metaphysical sense , we can never be 100.00 % sure of any of our knowledge . Just because all humans always have experienced the existence of the world , does n't mean that it is 100.00 % certain , just that the probability that it is true approaches 100.00 % ( say , 99.9999999 % ) . The greater the amount of evidence , the closer that certainty is to 100.00 % . That 0.0000001 % leaves room for obsurd scenarios - such as that an omnicient being is causing us all to merely imagine our reality , or the scenario of the movie `` The Matrix `` . These can be fun to ponder ( especially in a social situation after a few drinks ) , but no one takes them seriously . If anyone did seriously live by the idea that the world may not exist , they would quickly do something stupid and die , or change their minds ."
"No-one experiences the existence of an outside world . Explanations such as the Matrix can explain sense impressions as well as some concept of 'external reality ' . We have no more evidence for one than the other . The fact no-one takes them seriously is a psychological point about human beings , nothing to do with reality per se ."
"If anyone did seriously live by the idea that the world may not exist , they would quickly do something stupid and die , or change their minds ."
"fact no-one takes them seriously is a psychological point about human beings , nothing to do with reality per se ."