A.T. Robertson Commentary 1 Corinthians 11:14

"Doth not even nature itself teach you, that, if a man have long hair, it is a dishonor to him?" — 1 Corinthians 11:14 (ASV)

Nature itself (η φυσις αυτη). He reenforces the appeal to custom by the appeal to nature in a question that expects the affirmative answer (ουδε). Φυσις, from old verb φυω, to produce, like our word nature (Latin natura), is difficult to define. Here it means native sense of propriety (cf. Romans 2:14) in addition to mere custom, but one that rests on the objective difference in the constitution of things.