Philosophy, meet adventure. Adventure, this is philosophy. Shmoopers, here they are, brought together for your delight in More's Utopia. Despite being concerned with lots of Big Important Themes, this is also a book about exploration: the benefits—and drawbacks—of discovering new places and new ideas. What if, like Hythloday, everyone who leaves Europe to go exploring comes back preferring the new place? Will it help us improve or just make everyone miserable? What ethical responsibilities do we have toward these new people? What if they don't believe in our laws and moral ideals? Even though no one is directly voicing these concerns, you can bet that they would have been on everyone's mind.
Utopia is not a book about exploration; it's just a convenient context for some philosophical speculations.
In the Renaissance, exploration and travel would have been luxuries only an elite few could have taken advantage of, so morality and exploration are actually incompatible.