Susan is largely driven by pity in taking responsibility for Friday and his future. A black African in London without any means of support and the inability to speak, Friday is in a very difficult situation, as Susan clearly recognizes. She herself was in a similar situation back in Bahia, so there’s an element of empathy here too. Susan stays with Friday, looking out for him and teaching him how to grow vegetables. She hopes that one day, he will be able to return to his native Africa. But at the moment, that’s not possible, as Friday will almost certainly be sold into slavery if he does.

At the same time, Susan feels a profound responsibility to tell Friday’s story. Or, rather, she hopes to tell his story through Foe, as she herself isn’t much good as a writer. As Friday himself can’t tell his own story, due to his tongue having been cut out, it’s left to Susan and Foe to decide what his story should be.

It’s more than likely that Coetzee intended this to be a metaphor for how African history has tended to be told from the perspective of White Westerners. In any case, Susan’s willingness to tell Friday’s story provides us with an additional reason why she’s prepared to take responsibility for Friday and his future.