Problem: Paul affirmed that it is against “nature” for men to have long hair (1 Cor. 11:14). But the vow of the Nazarite demanded that one not cut his hair.
Solution: The general rule was for men not to dress like women (see comments on Deut. 22:5), nor to wear long hair like women (see comments on 1 Cor. 11:14). Any exception was born out of either perversity (e.g., homosexuality), necessity (health, safety), or special sanctity. The vow of the Nazarite falls into the latter category and is an exception that helps establish the rule. God wished to distinguish the sexes for purposes of social and moral propriety. However, a special vow of dedication to God involving long hair but not wearing women’s clothes would scarcely tend to violate the spirit of the divine design of keeping the sexes distinguishable. No one with evil intentions of confusing the sexes for perverse reasons would be making such a self-sacrificing spiritual vow.