Thomas More's general conception of an ideal state is unmistakably drawn from Plato. Elucidate.
More was a humanist, well-versed in classical literature. He had read Plato's Republic along with many other works from Ancient Greece and Rome. Certainly the two works share much in common. Both are intended to critique their own societies by theorizing about an ideal society.
Both works proceed from an important conclusion—that private property rights have to be abandoned in an ideal society. In both Plato's Republic and More's Utopia, property is held in common, because that is the only way that the people will be motivated to abandon self-interest and do what is best for the polity as a whole. (Plato limited this restriction on property ownership to the so-called "guardians" of the city.)
But there are also many differences between the two. Some scholars argue that More, like most intellectuals of his time, was perhaps more influenced by Aristotle than Plato. It is perhaps best to say that More was inspired by the project set forth by Plato's Republic—the attempt to outline what the ideal society might look like given the realities of human nature.
Overall, rather than being inspired by a specific work, Utopia is a work influenced by humanism, with his emphasis on classical texts, in general. The book is full of classical references, and the idea of the perfect society as a literary theme was well established in ancient times as well as More's own Christian context, which emphasized man's beginnings in Eden.
Thomas More's ideal state in "Utopia" is very similar to the ideal society laid out by Plato in "The Republic."
Both of these two works have the same main thesis. This is that an ideal society can only exist if they people of the society subordinate their own personal desires and rights to the needs of the society as a whole. For More, this means that people will give up private property, which will instead be held in common. For Plato, the rulers and leaders of society will submit to a strictly regimented life because that is what will be best for society.
While this overarching similarity is by far the most important, it is also interesting to note that both thinkers argue for the equal treatment of men and women.
Thomas More's Utopia, first published in Latin in 1516, was perhaps the greatest humanist reform tract of the Renaissance. The work presented a 'perfect society', authoritarian and fictional in its religious, social and political aspects. Indeed, the idea of an ideal state is what Plato's Republic and More's Utopia share, both the works taking a similar stance in their economic systems with regard to the distribution of good and acquisition of wealth.
Both Plato and More were guided by the notion of collective / social good, looking for a state rather abstract and fictional. More's tract with its more pronounced communist / socialist connotations--absence of private ownership and suppression of individuals by the society--looks forward to Karl Marx as it looks back to plato in its general design of a commonwealth.
Both have a generally similar main thesis.