If there is a heaven and you get there, could you still sin? If not, why not, if you're still free? If there is a hell and you end up there, why couldn't you choose to repent and get out? If not, why not, if you're still free? However esoteric these questions may seem, they forced thinkers in the fourteenth century to think hard about just what it is to be free. In what, exactly, does human freedom consist? By addressing a number of theological 'limit situations', such as those mentioned above, Robert Greystones, while at Oxford University in the 1320s, developed his own philosophical theory...