I've put in so many enigmas and puzzles that it will keep the professors busy for centuries arguing over what I meant, and that's the only way of insuring one's immortality.
— James Joyce

I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth.
Umberto Eco enigma quote

I cannot forecast to you the action of Russia. It is a riddle wrapped in a mystery inside an enigma; but perhaps there is a key. That key is Russian national interest.
— Winston Churchill

Without the spiritual world the material world is a disheartening enigma.
— Joseph Joubert

Russia is a riddle wrapped in a mystery inside an enigma.
— enigma quotation by Winston Churchill