PaulErdoslikedtotalkaboutTheBook，inwhichGodmaintainstheperfectproofsformathematicaltheorems，followingthedictumofG.H.Hardythatthereisnopermanentplaceforuglymathematics.ErdosalsosaidthatyouneednotbelieveinGodbut，asamathematician，youshouldbelieveinTheBook.Afewyearsago，wesuggestedtolumtowriteupafirst（andverymodest）approximationtoTheBook.Hewasenthusiasticabouttheideaand，characteristically，wenttoworkimmediately，fillingpageafterpagewithhissuggestions.OurbookwassupposedtoappearinMarch1998asapresenttoErdos'85thbirthday.WithPaul'sunfortunatedeathinthesummerof1996，heisnotlistedasaco-author.Insteadthisbookisdedicatedtohismemory.