这句话我理解起来有点困难。觉得把possible 和feasible对换一个位置才顺-不论原文怎么说的。
"Peer review, while theoretically feasible, is impossible in reality. “  》"Peer review, while theoretically possible, is unfeasible in reality. “  
OR 
"Peer review, while theoretically possible, is unfeasible under the circumstances. “