At the beginning of Chapter 2, the viacar makes it clear that when he is speaking of monogamy he is speaking about NO REMARRIAGE, not polygamy.

"...there was a peculiar tenet which I made a point of supporting: for I maintained with Whiston, that it was unlawful for A PRIEST (emphasis mine) of the Church of England, after the death of his first wife, to take a second, or, to express it in one word, I valued myself upon being a strict monogamist."