1 FIFTY YEARS OF PROSPECTING LINEAR PERSPECTIVE AND FINALLY FINDING THE GOLD: THE SENSIBLE HORIZON By Samuel Y. Edgerton A half century ago in 1965, I defended my PhD dissertaon before the art history faculty of the University of Pennsylvania. My thesis was entled Alber’s Opcs, a curious subject at a me when art history studies in America were more concerned with aesthec formalism. Sll, in spite of my dense dissertaon, weighted as it was with Lan references to the medieval science of geometric opcs, the faculty passed me and awarded the degree in 1966. Thus began my career as a professional art historian. My first determinaon as a newly-minted scholar was to publish my dissertaon and make my case which basically had to do with why, how and by whom Renaissance linear perspecve was first conceived. At that me my subject had lile appeal to the art book market. I had to wait nine more years and one job disaster before my dissertaon, now retled The Renaissance Rediscovery of Linear Perspecve was at last published in 1975. 1 As expected, the book was a slow seller. The publisher even reprimanded the editor who had advised him to accept it. Furthermore, the first readers were not art historians but historians of science who apparently found it more relevant to their discipline. The few art historians who did pick it up were generally unimpressed and gave it only tepid reviews. Nevertheless, Renaissance Rediscovery prevailed. In fact it has been reprinted twice since 1975, most recently in 2004, 2 and translated into German in 2002 as Die Entdeckung der