This two-volume set, Poesy Matters and Other Matters, presents selected texts by the Swedish polymath Catherine Christer Hennix. Volume one, Poesy Matters, is divided into two sections: poetry and drama, with each section also containing pieces of commentary by Hennix or her longtime collaborator Henry Flynt. Volume two, Other Matters, is divided into two sections: first, program notes and essays about a wide range of topics (including music, psychoanalysis, and mathematics), and second, a reproduction of Hennix's 1989 work The Yellow Book. The first comprehensive publication of Hennix's written work, Poesy Matters and Other Matters illustrates the singular depth and variety of her contributions to contemporary music, art, literature, and mathematics. Best known as a composer, Catherine Christer Hennix has, throughout her fifty-plus-year career, produced innovative work in the fields of not just minimal and computer music, but psychoanalytic theory, intuition mathematics, poetry, and prose as well. The texts in Poesy Matters and Other Matters reflect Hennix's diverse training as well as her long-standing personal interests in Lacanian psychoanalysis and Japanese and Middle Eastern poetic forms, resulting in a rich, diffuse collection of writings that reveal one of the avant-garde's most implacable, not to mention overlooked, creative minds.