So far we have seen that Nietzsche's perspectivism dispenses with Kant's oscillation between realism, entailing a God's Eye View, and idealism, where reality is thought to be reducible to the forms of our knowledge. The following three chapters show how Nietzsche's will to power thesis plays an important role in overcoming this oscillation. The present chapter does this by examining the arguments informing Nietzsche's proposal of the will to power, demonstrating that it operates as a metaphysics that not only derives from his perspectival account of knowledge but, as a result of its doing so, challenges traditional substantialist accounts of the nature of self and world. Denying that reality is a non-relational thing-in-itself knowable only by extra-perspectival means on the one hand, or that it is reducible to human minds on the other, Nietzsche puts forward the thesis that forces motivated by the desire for power are the ultimate constituents of reality and that both self and world are composed of these forces. However, in light of the Nietzsche literature to date the suggestion that Nietzsche proposes the will to power as a metaphysical thesis is controversial. Responses to the doctrine among Nietzsche commentators have been mixed and can be divided into two groups. Members of the first group, appealing to Nietzsche's perspectivism and playing down the significance of the will to power thesis, argue that Nietzsche is not a metaphysical thinker. Proponents of the second view, however, emphasising his comments on the will to power, argue that Nietzsche's philosophy is predominantly metaphysical.