Pronoun pitfalls

Pronouns, recall, refer to antecedents, to nouns that have gone before. A mistake you see in a lot of writing is to use a pronoun whose antecedent is unclear, or that lacks an antecedent altogether. In this passage, the pronoun they isn't set up well:

　　Machiavelli feels that Paganism favored freedom. They praised glory and war, unlike Christians. More inclined to fight fiercely, they were better able to defend freedom.

　　The writer here thought that referring to Paganism established the idea of Pagans. But it doesn't, and readers will be a bit confused and then irritated at having to make this connection themselves. The revision is simple:

　　Machiavelli feels that Paganism favored freedom. Unlike Christians, Pagans praised glory and war. More inclined to fight fiercely, they were better able to defend their freedom.

　　How can you tell when it's okay to use pronouns and when you should repeat the noun? Four rules of thumb:

　　1. Make sure it's clear what the antecedent is.

　　2. Use the noun, not a pronoun, if there's some confusion about what the antecedent would be:

ORIGINAL REVISION
Leonardo studied in Florence in the famed workshop of Andrea del Verrochio. He had been trained as a goldsmith, and this proved to be a major influence on Leonardo's work.
Leonardo studied in Florence in the famed workshop of Andrea del Verrochio. Verrochio had been trained as a goldsmith, and this proved to be a major influence on Leonardo's work.