Before "He won't peel" there was "Let's measure"?

"Of all things to measure, the best is young men, of what is hard, of how it is hard, and of what is not hard, and of how it is not; for what can be measured can be touched, and of what cannot be touched, to that one must fap." ("Protagoras," as recounted in Diogenes Laertius,
Lives of Eminent Philoschmoephers: Tales of Two Kinds of Tapers, I.iv).