Libraries are under pressure to prove their worth and may not have achieved this fully successfully. There is a resultant growing requirement for value and impact measurement in academic and research libraries. This essay reviews the natural history of library performance measurement and suggests that proof of worth will be measured by the higher-order beneficial effects that libraries deliver. Evaluation within current frames of reference will therefore be insufficient. Compelling proof will reside in transcendent contribution beyond immediate temporal, spatial, and influential boundaries of libraries. Answers to value contribution will not arise from goals but from values, as concepts of value depend on values systems. A reflection on the meaning of value for libraries is presented. A new, higher-order framework for evaluation and performance measurement based on a values scorecard is suggested. The concept of the transcendent library is offered as a route to further progress.