To Sir, With Love shows how society needs teachers.
To Sir, With Love shows the socially developmental importance of teachers in a couple of ways. One instance is in how Braithwaite teaches the lowest of the low students. He teaches students who are going to reach the age of adulthood soon and will be expected to be productive members of society. He teaches the students who are discarded. At the time Braithwaite reaches them, they have only a year left of study before adult responsibilities are thrust upon them.
Consider for a moment what might have happened had Braithwaite not been there. The class had already run out "Old Hack" as he had given up on them. While Braithwaite struggles mightily, his efforts result in them actually becoming something. He enables them to think about themselves in "promising situations" and to make something out of their lives. A teacher was responsible for this. Had Braithwaite not been there, the trajectory of their lives would have looked profoundly different. He was able to help them envision something previously unseen. As a result, he is able to create individuals who will give back to society. Braithwaite's efforts show the social importance of teachers.
The role of surrogate parent is another way in which the role of a teacher is explored in the text. Braithwaite comes to be accepted in the community because the parents recognize his care for their children. As their children come home and invariably talk about what he is doing for them, Braithwaite achieves a position of respect amongst the parents. This position is reflective of how a good teacher is valued in society. Society recognizes teachers as surrogate parents and individuals who craft the hearts and minds of the younger generation. Braithwaite's social acceptance is a confirmation of this belief.