Nietzsche’s philosophy was unique in the metaphysical tradition of the West, because he was the first person to recognize that the will to power posits all values, which are the means to prolong the act of willing and to become stronger. By fixing all value within “the preservation-enhancement conditions” of everything that is, Nietzsche established truth as that in which a “constant reserve” holds sway and remains at the disposal of the will. The will to power fixes in place that which provides for its own preservation and enhancement. Whatever does this most effectively is most true.
Heidegger's reading of Nietzsche's overman coincides with this notion of the will to power. The overman symbolizes humanity in its current, technological understanding of being. The will to power determines the overman, urging him to gain control of all that is. Yet this making secure by willing domination over everything remains inextricably linked to the positing of values. The overman, through the value-positing of the will to power, obviates the possibility of understanding being as something outside of his power, something in virtue of which anything stands out as meaningful for him. For Heidegger, the overman's will to power, as that which posits value onto being, does not remain receptive to being, but rather blocks off its essence in advance by treating it as a value.