Almost everything about More's Utopia is debatable, but at least the general subject-matter of the book is not in doubt. More announces his theme on the title page, which reads: De Optimo reipublicae statu deque nova insula Utopia. His concern, that is, is not merely or even primarily with the new island of Utopia; it is with ‘the best state of a commonwealth’.

To say that this is More's concern is at once to raise what has always been seen as the main interpretative puzzle about his book. Does he intend us to take the description of Utopia in Book II as an account of a commonwealth in its best state? Are we intended to share and ratify the almost unbounded enthusiasm that Raphael Hythloday, the traveller to Utopia, displays for that island and its way of life?

Until recently More's interpreters tended to answer in the affirmative. One theory has been that More aimed to picture the best state that reason can hope to establish in the absence of revelation. Another suggestion has been that he not only sought to portray a perfectly virtuous commonwealth, but wished at the same time to convey that, in spite of their heathenism, the Utopians are more truly and genuinely Christian than the nominally Christian states of western Europe. While disagreeing on the extent to which More holds up Utopia as an ideal, both schools of thought accept that Utopia must in some sense be regarded as an ideal commonwealth.