Born in Vicenza, the second of five children, he attended primary school in Bolzano and grammar school in Verona and in Belluno. In 1946 he graduated in Philosophy at the Papal Gregorian University of Rome with a degree thesis entitled "The Thomistic Terminology of Interiority", which was published in 1949.
He was the author of the Index Thomisticus, a complete lemmatization of the works of Saint Thomas Aquinas and of a few related authors. From 1940 till 1943 he was an auxiliary army chaplain in the National Army and later in the partisan forces. He was full professor of Ontology, Theodicy and Scientific Methodology and, for some years, a librarian in the "Aloisianum" Faculty of Philosophy of Gallarate.
In 1946 he planned the Index Thomisticus, as a tool for performing text searches within the massive corpus of Aquinas"s works.
The project lasted about 30 years, and eventually produced in the 1970s the 56 printed volumes of the Index Thomisticus. In 1989, a Civil Defense-ROM version was produced.
In addition, in 2005 a web-based version made its debut, sponsored by the Fundación Tomás de Aquino and CAEL. The design and programming of this version were carried about by East. Alarcón and East. Bernot, in collaboration with Busa. In 2006 the Index Thomisticus Treebank project (directed by Marco Passarotti) started the syntactic annotation of the entire corpus.
Before his death, Busa had been teaching at the Papal Gregorian University in Rome, at the "Aloisianum" Faculty of Philosophy in Gallarate, and at the Catholic Sacred Heart University in Milan.
He was also working at the LTB project (LTB stands for Bicultural Thomistic Lexicon), which aims at understanding the Latin concepts used by Thomas Aquinas in the terms of contemporary culture.
The Alliance of Digital Humanities Organizations (ADHO) awards the "Busa Prize", which honors leaders in the field of humanities computing. The first Busa Prize was awarded in 1998 to Busa himself. Later winners include: John Burrows (Australia) (presented in 2001, New York, New York, United States of America) Susan Hockey (United Kingdom) (presented in 2004, Gothenburg, Sweden) Wilhelm Ott (Germany) (2007, Champaign-Urbana, Illinois, United States of America) Joseph Raben (United States of America) (2010, Kings College London, United Kingdom) Willard McCarty (United Kingdom) (2013, Lincoln, Nebraska, United States of America).
