Nature without learning is like a blind man; learning without nature is like the maimed; practice without both these is incomplete. As in agriculture a good soil is first sought for, then a skilful husbandman, and then good seed: in the same way nature corresponds to the soil; the teacher to the husbandman; precepts and instruction to the seed.
In: Craufurd Tait Ramage, Beautiful Thoughts from Greek Authors (p. 283)