In this article, taking three selected works by the Danish artist Julie Nord as my point of departure, I will analyse and discuss the role of art in educational theory and practice. In this analysis and discussion I present two concepts, 'resistance' and 'undecidability', which are rooted in the theories of Dutch professor of education and director of research Gert Biesta and the French philosopher Jacques Derrida, respectively. The two concepts are used to analyse the three works of art and then come to grips with the empirical part of the study. The empirical part explores how a Danish fifth-grade class (ages 11-12) interacts with works of art characterised by these very things, resistance and undecidability. The point the article makes is that it is not always what is easy and unambiguous that offers the best conditions for learning and gives school pupils a desire to learn. Rather it is often what is full of resistance and is difficult to decipher and understand.