OをＣとみなす，考える
基礎レベル Sunshine 3, Lesson 5 より
❑ People regarded it as medicine.
as はあとに 名詞のほかに 形容詞や前置詞句などがきます。as の品詞を特に定めようとせずに，補語の目じるし と考えるのが明快です。
❑ I regard world peace as most important. (WISDOM)
cf. It was regarded as medicine.
cf. World peace is regarded as most important.
cf. think of /look on /see / O as C