That’s not why we carry on as if a material universe exists. We do that because following that hypothesis seems to work and matches the evidence we see in our lives. If we found that people we were talking to suddenly disappeared and turned up 100 miles away, we might carry on differently.
Similarly we assume that the sun is coming up the next morning. Even if we have a big test the next day and wouldn’t feel too upset if it went nova instead.
This book is almost twenty years old and is the only book by this author. I can’t find anything of substance about who he is and what his qualifications are. What caused you to dive into this obscure and unacclaimed book?