Subject sensitive invariantism is the view that whether a subject knows depends on what is at stake for that subject: the truth-value of a knowledge-attribution is sensitive to the subject's practical interests. I argue that subject sensitive invariantism cannot accept a very plausible principle for memory to transmit knowledge. I argue, furthermore, that semantic contextualism and contrastivism can accept this plausible principle for memory to transmit knowledge. I conclude that semantic contextualism and contrastivism are in a dialectical position better than subject sensitive invariantism is. © 2007 The Author.