In contemporary Nietzschean scholarship, some interpreters have emphasized the will to power as a psychological principle because Nietzsche applies it most frequently to human behavior. However, in Nietzsche's unpublished notes (later published by his sister as "The Will to Power"), Nietzsche sometimes seemed to view the will to power as a more (metaphysical) general force underlying all reality, not just human behavior—thus making it more directly analogous to Schopenhauer's will to live. For example, Nietzsche claims the "world is the will to power—and nothing besides!". Nevertheless, in relation to the entire body of Nietzsche's published works, many scholars have insisted that Nietzsche's principle of the will to power is less metaphysical and more pragmatic than Schopenhauer's will to live: while Schopenhauer thought the will to live was what was most real in the universe, Nietzsche can be understood as claiming only that the will to power is a particularly useful principle for his purposes.
Some interpreters also upheld a biological interpretation of the Wille zur Macht, making it equivalent with some kind of social Darwinism. For example the concept was appropriated by some Nazis such as Alfred Bäumler, who may have drawn influence from it or used it to justify their expansive quest for power.
This reading was criticized by Martin Heidegger in his 1930s courses on Nietzsche—suggesting that raw physical or political power was not what Nietzsche had in mind. This is reflected in the following passage from Nietzsche's notebooks:
Opposed to a biological and voluntary conception of the Wille zur Macht, Heidegger also argued that the will to power must be considered in relation to the Übermensch and the thought of eternal recurrence—although this reading itself has been criticized by Mazzino Montinari as a "macroscopic Nietzsche". Gilles Deleuze also emphasized the connection between the will to power and eternal return. Both Jacques Derrida and Gilles Deleuze were careful to point out that the primary nature of will to power is unconscious. This means that the drive to power is always already at work unconsciously, perpetually advancing the will of the one over the other. This thus creates the state of things in the observable or conscious world still operating through the same tension. Derrida is careful not to confine the will to power to human behavior, the mind, metaphysics, nor physical reality individually. It is the underlying life principle inaugurating all aspects of life and behavior, a self-preserving force. A sense of entropy and the eternal return, which are related, is always indissociable from the will to power. The eternal return of all memory initiated by the will to power is an entropic force again inherent to all life.
Opposed to this interpretation, the "Will To Power" can be understood (or misunderstood) to mean a struggle against one's surroundings that culminates in personal growth, self-overcoming, and self-perfection, and assert that the power held over others as a result of this is coincidental. Thus Nietzsche wrote:
It would be possible to claim that rather than an attempt to 'dominate over others', the "will to power" is better understood as the tenuous equilibrium in a system of forces' relations to each other. While a rock, for instance, does not have a conscious (or unconscious) "will", it nevertheless acts as a site of resistance within the "will to power" dynamic. Moreover, rather than 'dominating over others', "will to power" is more accurately positioned in relation to the subject (a mere synecdoche, both fictitious and necessary, for there is "no doer behind the deed," (see On the Genealogy of Morals)) and is an idea behind the statement that words are "seductions" within the process of self-mastery and self-overcoming. The "will to power" is thus a "cosmic" inner force acting in and through both animate and inanimate objects. Not just instincts but also higher level behaviors (even in humans) were to be reduced to the will to power. This includes both such apparently harmful acts as physical violence, lying, and domination, on one hand, and such apparently non-harmful acts as gift-giving, love, and praise on the other—though its manifestations can be altered significantly, such as through art and aesthetic experience. In Beyond Good and Evil, he claims that philosophers' "will to truth" (i.e., their apparent desire to dispassionately seek objective, absolute truth) is actually nothing more than a manifestation of their will to power; this will can be life-affirming or a manifestation of nihilism, but it is the will to power all the same.
Other Nietzschean interpreters dispute the suggestion that Nietzsche's concept of the will to power is merely and only a matter of narrow, harmless, humanistic self-perfection. They suggest that, for Nietzsche, power means self-perfection as well as outward, political, elitist, aristocratic domination. Nietzsche, in fact, explicitly and specifically defined the egalitarian state-idea as the embodiment of the will to power in decline: