Her book, Angels and Insects, straddles this divide. The volume is made up of two novellas - "Morpho Eugenia" and "Conjugial Angel", which are thematically, if not narratologically related. Although I enjoyed "Morpho Eugenia" a great deal more than "Conjugial Angel", I can see why Byatt chose to put them next to each other in this volume. Together, they offer a novel length examination of the relationship between science and religion as it was being explored in the mid-19th century, and as it is still being explored today.
"Morpho Eugenia" tells the story of a naturalist, William Adamson, recently returned from the Amazon and welcomed into the marbled household of his patron, Harald Alabaster. Byatt parallels William's enchantment with the Alabaster family, particularly the pale, beautiful Eugenia, with his study of insects until, through William's disenchantment, the reader is brought to see how human beings and insects are similarly ruthless, and misunderstood. All of this is set against the competing backdrops of evolution vs. faith, and reality vs. fantasy, which Byatt weaves with the threads of Milton's Paradise Lost, a fictional religious treatise, etymology and several invented fairy stories.
"Conjugial Angel" occupies an entirely different tone and space than does "Morpho Eugenia". Whereas Byatt concerns herself with the base root of humanity in the first of the two, "Conjugial Angel" poses questions about things of a spiritual nature through the strange happenings at a Victorian seance. Though decidedly more tongue-in-cheek than "Morpho Eugenia", "Conjugial Angel" lacks its companion's depth and clarity, though it is far from substance-less. While I would recommend "Morpho Eugenia" to anyone as a stand alone (with the slight warning that it is a stylistic pastiche), I cannot do the same for "Conjugial Angel." However, read in their intended pairing, both stories work beautifully as an overall exploration of faith, science and the changing nature of love.