It's about life.....
If you have more money and you don't have any knowledge....you can't see the world properly.....that's why some rich people doesn't care about others or some don't even know how real world is cuz they don't go out from their mansion/castle.....or whatever
AND
Same goes with the other two....the person standing on books and the person standing on the floor....
SO
You might probably need both money and knowledge to see and understand the world.....or whatever..
P.S.- The books represent knowledge and money represent.......well....money
P.S.(2) - Hope you understood because I'm not very good at explaining things....so if there're any mistakes pls let me know...