The Plants of Middle-Earth: Botany and Sub-Creation
"Rather than inventing an alien world into which human and familiar characters are introduced, as in science fiction, Tolkien created a natural environment that is also home to 'supernatural' beings and elements, as in medieval works like Beowulf. The Shire is always the touchstone to which the hobbits return mentally and against which they (and we) measure the rest of Middle-earth. By creating a sense of familiarity and belonging early and then in each of the cultures encountered, we can meet 'others' without feeling estranged."