Can reason lead us in directions that are good or decent or moral? After all, you pointed out that reason is just a means to an end, and the end depends on the reasoner's passions. Reason can lay out a road map to peace and harmony if the reasoner wants peace and harmony, but it can also lay out a road map to conflict and strife if the reasoner delights in conflict and strife. Can reason force the reasoner to want less cruelty and waste?
Steven Pinker
reason, ted-talks