Ignoramus et ignorabimus!

In 1880 Emil du Bois-Reymond outlined seven "world riddles" some of which, he declared, neither science nor philosophy could ever explain. Concerning numbers 1,2 and 5 he actually proclaimed: "we do not know and will not know."

1. The ultimate nature of matter and force;
2. The origin of motion;
3. The origin of life;
4. The "apparently teleological arrangements of nature," not an "absolutely transcendent riddle";
5. The origin of simple sensations, "a quite transcendent" question;
6. The origin of intelligent thought and language, which might be known if the origin of sensations could be known;
7. The question of freewill;

The fifth one is particularly interesting. Quoting Schrodinger: "we simply cannot see how material events can be transformed into sensation and thought..."

Complain all you want! He may be right...