The situation reflected in this cartoon of course is comic and hyperbolized. However we can meet such a case in our life, too. The main idea is that even human being do not know nothing about the theme and is not aware of topic discussed or explored, he/she can make a conclusion from previous experience and so find out if answer to the discussed topic is right or wrong. If we once have been told, that 2+2=4 and have believed in this statement, consequently we have acquired a knowledge, even it cannot be checked, then if the next time we will be told that 2+3=4 we will not believe in it, because we have a previous experience and, that 2+2=4. …