De Martelaere was reluctant to seek publicity and preferred her work to speak for itself. She rarely gave interviews, instead writing essays and giving lectures about her field, ideas, work as an author. Her primary theme was to examine with great lucidity and philosophical insight the world of everyday life, death, and change, including both scientific and literary perspectives. Her literary works were realized by observing reality and processing her observations into ideas and metaphors. In one of her rare interviews she described her method as "plagiarizing reality." She achieved considerable success in Flanders and the Netherlands with her first collection of essays,
Een verlangen naar ontroostbaarheid (
A Longing for Inconsolability: About Life, Art and Death), with sales over 15,000 copies. De Martelaere treats ostensibly difficult subjects such as Wittgenstein, Freud, art, religion, diaries, and love in ways that are philosophically serious without alienating the general reader. One review hails "her obstinacy, perverse and infectious sense of humour, courtly style, and deep erudition."
Verrassingen (
Surprises) was her next collection of eleven essays, the first of which is "Home: A Place to Get Sick of". She alternates between literature and philosophy, referring to Freud, Jung,
Stendhal, and
Valéry, asserting that "home is where the boredom is: a kind of psychic relaxation that makes psychological space for the re-emergence of inspiration." In "The Exemplary Writer" she questions the position of
Richard Rorty that literature is best used to promote feelings of solidarity and empathy between people. From both ethics and literature she considers the mystery by which artists may attempt to reveal in their art more than what can be seen or said. This ethical meaning of art should never be made subordinate to an interpretation or message. The essay "Prescribed Variations" on concepts such as "seeing", "longing", "body" and "moon" "have the density of aphorisms and reveal De Martelaere’s astounding capacity to express complex material clearly while immediately linking it to a challenging vision. An essay, as she states earlier in the book, is born of the paradoxical desire to explain and adorn reality, it longs to explore and to embellish. It is like a trial marriage between Einstein and Marilyn Monroe." In
The Unexpected Answer she does not allow the writer, philosopher, husband, lover, and father Godfried H. to speak, but makes him instead the subject of six texts written from the points of view of the women who play a role in his life. The first draws his portrait. Initially she keeps her distance, later she embarks on an unexpected and brief relationship with him. Thus De Martelaere illustrates her claim that language is "not a tool" but "material" to an author. ==Philosophical works==