THE SEVEN WORLD-PROBLEMS. 447 



could imagine the mechanism of the world to consist only of reversible 

 processes, and that at a given instant the motions of all the particles 

 of matter were reversed as a ball is knocked back, then the history of 

 the material world would play itself over again backward. All that 

 now happens would come to pass again after its time in the inverse 

 order : the ben would become an egg again, the tree would grow back- 

 ward into a seed, and after an infinite time the cosmos would be 

 resolved again into chaos. What processes would now attend tbe 

 reverse movements of the brain -molecules ? If mental conditions de- 

 pended only on arrangements of atoms, then with the same arrange- 

 ments the same conditions would return, leading to surprising results ; 

 among them, that, always at tbe instant before we contemplate any- 

 thing, the counterpart of it would happen. We may, however, spare 

 ourselves from estimating the possibilities thinkable here. The crank 

 of the world-machinery could not be thus turned backward. The 

 motion of masses, for instance, which has been converted by friction 

 into heat, could not be changed back again into the same amount of 

 similarly adjusted, opposite-faced motion. The reversed world is a 

 bit of impossible mechanical fancy-work, from which nothing can be 

 drawn respecting the origin of consciousness and free-will. 



Our seventh difficulty becomes no longer a difficulty, provided we 

 determine to deny free-will, and to declare the subjective feeling of 

 freedom a delusion ; but otherwise it must be regarded as transcend- 

 ent ; and it is but a poor consolation to monism that it sees dualism 

 entangled in the same net the more helplessly as it lays more stress 

 on ethics. In this sense I once wrote, in the preface to my " Unter- 

 suchungen iiber thierische Elektricitat " (" Researches on Animal Elec- 

 tricity"), the words upon which Strauss now appeals against me : 

 "Analytical mechanics reaches to the problem of personal freedom, 

 the solution of which must remain an affair of the abstractive faculty 

 of each individual." But afterward and I make no secret of it 

 the day of Damascus came to me. Repeated reflections on the subject 

 of my public address, " Ueber einige Ergebnisse der neueren Natur- 

 forschung " (" On some Results of the Later Natural Philosophy "), led 

 me to the conviction tbat at least three transcendental problems pre- 

 cede the problem of free-will, viz., besides the problem of the origin 

 of matter and force, which I have previously defined, that of the first 

 motion and that of the first sensation, in the world. That the seven 

 world-problems have been counted out and numbered here as if in a 

 mathematical book of examples, has come to pass in consequence of 

 the scientific divide et impera. We might combine them into a single 

 problem the world-problem. The mighty thinker whose memory we 

 honor to-day believed that he bad solved this problem. He had ar- 

 ranged the world to his satisfaction. Could Leibnitz, standing on his 

 own shoulders, take part in our reflections to-day, he would surely say 

 with us, " Dubitemus.'''' 



