Paul Preuss has shaped the history of alpinism like few others. Exactly 100 years ago, his essay "Artificial Aids in High Altitudes" sparked a debate within the climbing elite that still resonates today. By advocating for pure climbing style without the use of hooks, he became known as the "inventor of free climbing" and supported his theories through visionary solo ascents in the Alps. Reinhold Messner introduces us to the "most complete mountaineer of the Alps" and explains why his ideas have lost none of their impact to this day.