Friedrich Nietzsche, the German philosopher and cultural critic, is perhaps best known for his declaration that "God is dead" and his belief in the concept of the "Übermensch," or superman. However, one of his lesser-known ideas is the concept that a "man of knowledge" must be able to not only love his enemies but also to hate his friends.
This idea is rooted in Nietzsche's belief in the importance of individuality and the rejection of conventional morality. In his view, traditional morality, which is based on the idea of good and evil, is overly restrictive and stifles the potential for individual growth. Instead, Nietzsche believed that individuals should strive to cultivate their own unique moral code, based on their own experiences and values.
According to Nietzsche, a true "man of knowledge" is someone who has the courage to reject conventional morality and create their own moral framework. This requires a willingness to challenge and even reject the beliefs and values of those around them, including their friends. In order to fully embrace their individuality, a "man of knowledge" must be willing to challenge and even hate their friends, if necessary.
At the same time, Nietzsche believed that a "man of knowledge" must also be able to love their enemies. This is because, in order to truly understand and overcome one's foes, one must be able to empathise with them and see things from their perspective. Only by understanding one's enemies can one hope to defeat them.
In this way, Nietzsche's idea of the "man of knowledge" is a complex and nuanced one. It requires a combination of both love and hate, as well as a rejection of conventional morality in favour of a more individualistic approach to ethics. Ultimately, it is a belief in the power of the individual to shape their own destiny and create their own moral code.