"I can do what I will: I can, if I will, give everything I have to the poor and thus become poor myself---if I will! But I cannot will this, because the opposing motives have much too much power over me for me to be able to. On the other hand, if I had a different character, even to the extent that I were a saint, then I would be able to will it. But then I could not keep from willing it, and hence I would have to do so."More famously this thought is encapsulated in the phrase: "Man can indeed do what he wants, but he cannot want what he wants." A thought Einstein found to be particularly comforting.
His idea is very subtle and bears repeated reading, but it comes down to what Schopenhauer calls "character", or the specific way the individual reacts to stimuli or "motive". This inevitably leads to a form of determinism, where one's character is fixed, and thus one's reaction's to life cannot be any other than they have been or will be:
"How is the tireless goodness of one human being and the incorrigible, deeply rooted wickedness of the other, the character of the Antonines, of Hadrian, of Titus on the one hand, and that of Caligula, Nero, Domitian on the other, supposed to have flown in from outside, and to be the work of contingent circumstances, or of mere cognition and teaching! After all, none other than Nero had Seneca as his educator. -- Furthermore in the inborn character, this real core of the whole human being, lies the germ of all his virtues and vices."Of course, our legal system is one based on the premise that people can and do change. However, if Schopenhauer is right, and this new research appears to be pointing in that direction, the whole way we conceive of crime and punishment will need to be rethought.