Opera Aperta is documentation of Ella Spitzer-Stephan’s year-long research on Martin Heidegger’s theory of “the Fourfold” from his book Poetry-Language-Thought. Ella uses his phenomenology as a basis for understanding the significance, and effects of Marginalia. Through the analysis of many library copies of the same text, Opera Aperta analyses the different forms of mark making applied within the gaps of the pages, and relates it to greater ideas of the transformative, living quality of writing. This work, existing both digitally and in print remains “unfinished” and will transform, as the library copies undergo further annotations, and as the artist conducts further research.