。
Seek advice from a wise and conscientious person.
Literal
Wise [and-で] conscientious person [from-に] advice [object-を] seek-[gentle-imperative-なさい].
A clean instructional sentence. ~なさい is a softened imperative used by parents to children, teachers to students, or in written instructions — firmer than a request but much less blunt than the bare plain-form imperative (求めろ). It derives from the honorific ~なさる, and still retains a slightly elevated, parental tone. 賢明で良心的な人 illustrates how two adjectives (one な-adjective, one ai-adjective in な-form) connect via the て-form of the copula: 賢明で + 良心的な. Note the particle on the person is に (dative/receiving), which is standard with 求める ('ask/seek from').