When Grant talks about only being able to teach what "they" want him to, I believe it's directly linked to the quotes of him talking to Paul of how he doesn't believe that he's "even a teacher," because "you have to believe to be a teacher." When you look at it this way, it appears that the reason he feels this way isn't because, no matter how hard he tries, or no matter what he teaches, he won't be able to make a positive impact on society or those that he teaches. Rather, it implies that he can't possible be a great teacher because he's unable to teach what he believes in and in order to be a great teacher, he would have to be allowed to do so. Only then would he even have been given the chance to be a great teacher (assuming that what he would choose to teach - being of course, the things he believes in - were helpful and more likely to matter or have an impact in some positive way). This gives Grant a bit of hope in terms of there being a possibility of him being a great teacher. Instead of saying that it's Grants shortcomings as a teacher or as a person, it puts the blame on the system in place, which he's been forced to abide by. While if Grant were simply a bad person and, therefore, a poor teacher, the effects of this - on his ability to truly educate and make a positive difference in his students' lives - may have been irreversable. However, it seems a less daunting task to change or simply work around the system in place, which has been limiting his potential. Of course, we can't completely rule out the possibility that the factor, which is limiting Grant's teaching abilities is the lesser of the two evils. We must ask why Grant has not already begun to do this, why he has so far incorporated "nothing about dignity, nothing about identity, nothing about loving and caring," into his teachings of "what they wanted [him] to do, teach reading, writing, and arithmetic.
