As far as I know, there is no proof whatever of the existence of an objective reality apart from our senses, and I do not see why we should accept the outside world as such solely by virtue of our senses. These reality enthusiasts are possibly playing at hide-and-seek; at any rate they like to hide themselves, though they are not usually aware of it. They simply do it because they happen to have been born with a sense of reality, that is, with a great interest in so-called reality, and because man likes to forget himself.