They rarely teach for its own sake but most of the time [they] use teaching as a way to manipulate.
Is it idiomatic to omit the second "they" in the above sentence?
They rarely teach for its own sake but most of the time [they] use teaching as a way to manipulate.
Is it idiomatic to omit the second "they" in the above sentence?
This ellipsis may be pushing the boundaries of good communication, but it is perfectly proper grammatically to use a single subject for multiple verbs.
"Mary wrote and sang the songs heard that night" is idiomatic and grammatical.
However, in your example, there is a fairly extensive bit of other material separating the verbs, and a skilled writer would likely respond to that separation either by repeating the subject or by bringing the two verbs closer together or by using parallelism. I might re-write as follows:
"They rarely teach to educate but instead teach to indoctrinate."
I want to stress that I am not taking a position on grammar. I am making a point on style.
It's pretty good with or without the second pronoun; I'd leave it out but it's not “wrong”.
Personally I'd add rather after the but.