He received his Ph.D. from the Faculty of Arts in 1960 with a focus on Baroque architecture in Ljubljana. He was one of the leading Slovenian conservators and is responsible for the renovation of Križanke with Jože Plečnik; the railway station with Marko Mušič, and other important buildings. He initially worked as a conservator at the City Museum of Ljubljana, and since 1962 has taught at the Department of Art History at the Faculty of Arts, where he was also the dean and founder of the Scientific Institute of the Faculty of Arts (ZIFF).

By founding ZIFF, Nace Šumi laid the foundations for the Slovenian history of art in the international frame, which was especially evident after 1990. His broad-mindedness gazed beyond the narrow local borders as he opened art history both in temporal and geographical terms. He facilitated the research and scientific collaboration not only to those of us who work at the Faculty of Arts but also those from other institutions that had proved themselves as researchers and wanted to broadcast their results. The internationally-oriented art history is a fruit of his thought from 1987.

I worked at the Scientific Institute of the Faculty of Arts for thirty years. Nace Šumi was a remarkable personality of broad views and deep thoughts, both within the profession and in the humanities in general. He knew how to connect people with one another and he knew how to think on behalf of other people and the wider humanistic community in Slovenia. One of his lifelong slogans was: "Dare to think!" Even today, people who had known him stick to those words. We still dare to think.

Nace Šumi was first and foremost my professor. In one word, his lectures were full. No platitudes, enumerations, or droning about dates, sizes, and shapes of paintings we covered. It was about the poetry of art history. He was one of the greatest experts on the Baroque. He was also a huge admirer of our grandest architect, Jože Plečnik. At his request, I assumed the position of Vice-Dean for Student Affairs, even though I was still the Head. That's when we started working together on running the "school" as he called the Faculty. We particularly cooperated on consolidating the belonging to the "school" and University among the colleagues, which is no longer cultivated nowadays. We clicked really fast on that front. His communication with everyone was quite known. He wanted to keep the faculty stick together in every way. He was full of ideas and visions of how to advance, create something new. The science institute was his idea and his child, similarly to the Department of Library Science. He used to say: "It can be done, we have to do it." He never gave up and since I saw myself in that, we quickly became close family friends. As he was leaving, he nominated me as the new President of the Institute Council. I won the election and I considered the victory to be an endorsement of the direction outlined by Professor Šumi; they saw in me a continuation of that direction. We have brought the research activity at the faculty quite far, we organized it and presented it, which is especially important.