The will to power () is a concept in the philosophy of Friedrich Nietzsche. The will to power describes what Nietzsche may have believed to be the main driving force in humans. However, the concept was never systematically defined in Nietzsche's work, leaving its interpretation open to debate. Usage of the term by Nietzsche can be summarized as self-determination, the concept of actualizing one's will onto one's self or one's surroundings, and coincides heavily with egoism. Alfred Adler incorporated the will to power into his individual psychology. This can be contrasted to the other Viennese schools of psychotherapy: Sigmund Freud's pleasure principle (will to pleasure) and Viktor Frankl's logotherapy (will to meaning). Each of these schools advocates and teaches a very different essential driving force in human beings. Kraft vs. Macht Some of the misconceptions of the will to power, including Nazi appropriation of Nietzsche's philosophy, arise from overlooking Nietzsche's distinction between Kraft ("force" or "strength") and Macht ("power" or "might"). Kraft is primordial strength that may be exercised by anything possessing it, while Macht is, within Nietzsche's philosophy, closely tied to sublimation and "self-overcoming", the conscious channeling of Kraft for creative purposes. Early influences Nietzsche's early thinking was influenced by that of Arthur Schopenhauer, whom he first discovered in 1865. Schopenhauer puts a central emphasis on will and in particular has a concept of the "will to live". Writing a generation before Nietzsche, he explained that the universe and everything in it is driven by a primordial will to live, which results in a desire in all living creatures to avoid death and to procreate. For Schopenhauer, this will is the most fundamental aspect of reality – more fundamental even than being. Another important influence was Roger Joseph Boscovich, whom Nietzsche discovered and learned about through his reading, in 1866, of Friedrich Albert Lange's 1865 Geschichte des Materialismus (History of Materialism). As early as 1872, Nietzsche went on to study Boscovich's book Theoria Philosophia Naturalis for himself. Nietzsche makes his only reference in his published works to Boscovich in Beyond Good and Evil, where he declares war on "soul-atomism". Boscovich had rejected the idea of "materialistic atomism", which Nietzsche calls "one of the best refuted theories there is". The idea of centers of force would become central to Nietzsche's later theories of "will to power". Appearance of the concept in Nietzsche's work As the 1880s began, Nietzsche began to