His chief occupation and enjoyment were controversy.
RULE V.
When an address is made, the noun or pronoun addressed, is put in the nominative case independent; as, "Plato, thou reasonest well;" "Do, Trim, said my uncle Toby."
NOTE 1. A noun is independent, when it has no verb to agree with it.
2. Interjections require the objective case of a pronoun of the first person after them, but the nominative of a noun or pronoun of the second or third person; as, "Ah! me; Oh! thou; O! virtue."
RULE VI.
A noun or pronoun placed before a participle, and being independent of the rest of the sentence, is in the nominative case absolute; as, "Shame being lost; all virtue is lost;" "The sun being risen, we travelled on."
NOTE. Every nominative case, except the case absolute and independent, should belong to some verb expressed or understood; as, "To whom thus Adam;" that is, spoke.